So I have

Poe Dameron 11 (33)

VI

Advanced Optics

BB8

Auto Thrusters

(40)

Fen Rau 9 (20)

Decoy

M9-G8

(25)

Cassian Andor 6 (27)

SnapShot

Maul

Ezra

Pivot Wing

(35)

Here with a target lock on the enemy ship you wish to fire upon you almost always get every dice a hit, spend the target lock to reroll blanks, if you got any blanks reroll again with maul while getting a stress, if you have a focus you can then change into a crit with ezra and thats, a 3/4 damage on the ennemy ship if it has bad rolls

Fen rau comes in support nerfing enemy attacker ships and helping cassian to get a focus action if needed (most of the time ezra is enough) so you want to get a target lock on the most threatening ship to your u-wing and also have him in your firing arc so you can take a stress and incapacitated his ability to use tokens, with M9 and the target lock you can force a reroll on a chosen red dice (applies on friendly ships also so tons of combination possible). Also i suggest to fly it a range 1-2 of the U-Wing because when fen rau takes a stress from his ability cassian removes it automatically at the activation phase, the sheatiped coordinate action takes place within range 1-2 and also the decoy at the start of the combat phase let you swap your PS9 to cassian, so cassian gets a better opportunity to take down baddies.

Poe do Poe things

The list his fairly tanky and maneuverable with a 5hp a 8hp and a 6hp with good damage so definitively my go to heading to tournament, i'm currently 3-1 against my friend and he hates it.

Feel free to propose any recommendations

So, first things first:

Poe is always a good choice these days, though he basically begs for his Black One - that's half the appeal.

Fenn is also a good choice, but I think you're running him too light. For crew/astro, I think the best choices are M9-G8/Weapons Engineer (support focused), or R3 Astromech/Kyle Katarn (survival focused). For EPT, nothing is wrong with Decoy, but it could be ditched.

Now, Cassian is where I waffle. U-Wings are thoroughly meh as a chassis. While Ezra/Maul is a great combo, I really question it on a U, as keeping a target in arc with that dial is very hard. I have seen good U-Wing builds, but I don't know if this will hold up. You might consider looking at the Expert Handling/Adv. Sensors/Kyle/Kanan/EI Cassian some people have pulled, or a more standard Hera/Ezra/seasonings.

Going into your first tournament you should give the rules a once over. In particular you mentioned "reroll again" with Maul, which is not allowed by the Rules Reference (p.13 under 'Modifying Dice') it's something to be aware of so you aren't planning on doing something that won't be allowed in a tournament.

As for the list itself, I feel like you're running everyone just a little lighter than they want to be, which is part of the challenge when running 100 point lists. Poe really wants his Black One title to ditch Target locks for the squad. Fenn could use an Inspiring Recruit to let Maul clear two stress on a hit or Cassian clear two stress on a green (after Maul misses) or his ability. 35 points is a bit low for Cassian, but he's the one that can most afford to run slim here... How much use do you get out of Snap Shot? If you had Fire Control System it would get you even more mileage by locking anything that happens to land in front of you regardless of if you got on the snap.

My recommendation for a list tweak would be to drop Snap Shot to a zero pointer (Adaptability and A Score to Settle would both be useful) and allocate those points to B1 on Poe and an IR for Fenn. With IR in the mix you can freely use Maul on two rerolls, add Score to Settle against the biggest target and you're pretty reliable.

Additionally, switch Fenn to VI for that super cool PS11 coordinate and token block. I really don't think it's a good plan to Decoy Fenn down from his high ps perch. Then drop Snap Shot and add in B1 and IR as above and you still have one point left over for Cassian's Elite slot or a small initiative bid.

Get Black One immediately. It's just too strong right now to skip.

I'll also second that VI is probably better than Decoy on Fenn Rau. He's not really boosting someone who needs to shoot first, and it'd be nicer to get high PS with him.

I'm not sure I like a Maul/Ezra U-Wing. One of the big strengths of Maul/Ezra is that it leaves you free to take action for defense or positioning. The U-Wing just has a defensive focus, which I don't think is that strong. On something like a Ghost or a Auzituck, there are Evade and Reinforce actions to take. However, a U-Wing does want some sort of consistent offensive modification, and Fire Control System doesn't really cut it with the U-Wing's dial and low mobility. Perhaps Accuracy Corrector is a good bet. I've been loving it on the TIE/SF I've been flying lately, and think it's probably a bit underrated.

Ok, so what next? This U-Wing is an interesting sort of support ship, so perhaps Jan Ors. She allows a one friendly ship a turn (even hers) to take Evade tokens instead of Focus, which seems really nice here. Advanced Optics Poe doesn't need to spend his focus, so being able to take an action to get an Evade token from Jan Ors would add a good degree of toughness there. Poe probably won't need to take a TL too often, since Fenn's M9-G8 can give him a reroll. Alternately, Cassian can just protect himself. The Evade is already better than a focus, statistically speaking, when you're on 2 agility, but if you flip your title and drop down to 1, it gets a lot better still. To that end, I've often found that when I get ready to stall my U-Wing, thinking I'd like to turn around, it's almost seemed better to just not turn around. I feel like once I telegraph my flip, my opponents try to get behind me, so a regular stall might be better.

As a second crew, I like Inspiring Recruit. It's just pretty handy. I'd put it on Cassian, but it could go on Fenn Rau instead.

I'm not super excited by Snap Shot. The list doesn't really have tools to take advantage of an attack which will probably miss. Snap Shot usually works best with things like Operations Specialist somewhere else in the list. Two out-of-the-box ideas could be Draw Their Fire, to steal a few crits away from another ship, or perhaps Expert Handling. Being able to move that large base in a surprise barrel roll can be great, and you'll still have offensive dice mods from Accuracy Corrector.