i've started a game for 20 turns need help

[Suicide Junkie]

Since you have physics lev 2, I suggest you research and use Phased polaron beams.
You'll be able to ignore the shields of the enemy when you meet them.

Since you don't have any enemies right now, I suggest you research construction, then fighters. Instead of spending points maintaining ships, you can spend points to build an unlimited number of fighters & other units.

Build anything that's maintenance-free.