I'm new to the fantasy flight star wars rpgs, could someone help me build a good melee assassin? I can't seem to think of anything. Any help would be appreciated

Not sure what you are asking for... are you asking for a build, or a concept?

Looking for a good build

Spy:infiltrator would probably be your career. It's pretty noob friendly too since its essentially just a single line.

For species you want something that will allow a good Agility and Brawn, with cunning likely being third.

For gear, look at compact concealable weapons like vibroknives, boonta blasters, throwing knives, and grenades. Equipment like comm scramblers, electronic lock breaks, concealing robes, banal clothing, and holographic costumes are good. Don't go overboard on armor. Armored clothing is probably all you'll need, unless you want to get uber expensive.

Can you elaborate a bit more what do you want?

Do you want a cunning stealthy character who is also proficient with close combat? or more a character who is a very good melee character who can kill enemies by the score?

I'd say Infiltrator or Assassin.

I am looking for a close combat specialist who also knows how to remain undetected. He will main a knife or a sword, but has some skill in guns.

I'd say Assasin.