If you roll no successes but you do roll advantages does something positive still happen?

Yes, check the combat section for a partial list of options for spending advantages. You can also apply similar spending in non-combat situations, just try to scale it similarly to the combat ones.

Yes. You can use it to recover strain, notice a weakness, shoot a console accidentally which closes the blast door, fire a stray bolt that hits the moon, reducing its wound threshold to 367, etc. One day moon...one day...

There are a only two things advantage can buy - that I can think of - that require a successful test: Crits, and secondary attacks.

There are many good posts on this already but in summary:

No successes means the check failed. You either succeed or fail at a check. Successes or failures generally don't influence how much you succeed or fail a check by. Advantages and disadvantages on the other hand are completely separate from success or failure.

Advantages directly influence how good a success is or add benefits to failure while disadvantages directly influence how bad a failure is or add complications to a success. Neither even need to be related directly to the task at hand.

Examples of failing a noncombat check with advantages:
• Under fire, you tried to leap over the obstacle and fell. You're now pinned but at least you have cover.

• You were unable to bypass mechanic lock but noticed an open window you may be able to climb up to.

• The mark heard you sneaking around but luckily no one fixed the faulty wiring and the light switch wouldn't work.

• A trooper saw through your lies but dropped his magnacuffs giving you an opportunity to attempt to flee.

Examples of succeeding a noncombat check with disadvantages:

• The computer was an easy slice however you failed to evade notice and triggered the silent alarm.

• You got out without being seen but forgot to reactivate the alarm which will cause suspicion.

• While negotiating prices with a dealer another customer recognizes your face from a bounty posting and sends an alert out.

• You fixed the hyperdrive but knocked loose a component without realizing which will cause problems later.

It's always up to the GM what happens but advantages will progress the story in a way beneficial to the party and disadvantages will progress the story in a way which is in some way detrimental. There is very little chance that a roll will never progress the story at all and those times are usually from the poor GM'ing practice of making players roll for checks that have no downsides to failing. Bolded because this point cannot be stressed enough, especially in EoTE.

Note: Combat, abilities, and the like may have some options for players to use advantages in order to directly influence results instead of the GM which is why I focused on the narrative side as it's a lot broader and GM controlled.

There are a only two things advantage can buy - that I can think of - that require a successful test: Crits, and secondary attacks.

If that's all you are spending advantage on, you're wasting a lot of advantage. Check out some of the posts here and in the Core Rulebook to see what advantage can be spent on. Spending advantage is independent of a roll succeeding.

Advantage can be used for a ton of things.

Give a setback or boost to someone. Maybe the guard you are trying to sneak past is sleeping or engrossed in the latest holonovel, that stormtrooper shooting at you happens to have misaligned his blaster's barrel and isn't shooting straight, etc...

Make something interesting happen. The lights suddenly cut out due to faulty wiring/a stray bolt hitting the main line, one of the guards you are fighting has an irrational fear of Wookies, the sleazy salesman you are negotiating with has a strong attraction to twi'lek females, the TiE fighter tailing you has a small malfunction in its left ion drive, etc...

There are a only two things advantage can buy - that I can think of - that require a successful test: Crits, and secondary attacks.

If that's all you are spending advantage on, you're wasting a lot of advantage. Check out some of the posts here and in the Core Rulebook to see what advantage can be spent on. Spending advantage is independent of a roll succeeding.

For more ideas on adjudicating dice results, check out Skill Monkey. Fiddleback is the man when it comes to getting those creative juices flowing.

So advantages are storytelling inspiration? So like you get no successes but 2 Advantages on a roll from doing something.. They dont succeed in the act but something beneficial will happen?

So advantages are storytelling inspiration? So like you get no successes but 2 Advantages on a roll from doing something.. They dont succeed in the act but something beneficial will happen?

Correct. Makes for a dynamic experience for the players.

So advantages are storytelling inspiration? So like you get no successes but 2 Advantages on a roll from doing something.. They dont succeed in the act but something beneficial will happen?

Exactly. Think of them as representing an unintended benefit. Similarly, Triumphs are also an unintended benefit(just a bigger one)

The inverse is also true.

Our GM is particularly fond of making our heavy blaster's overheat.