Asteroids using gl4java

I''m making my own version of the 80''s game Asteroids as a first game attempt but i''m having trouble grasping 2d movement. I''ve looked through past topics etc and checked nehe and other sites but haven''t found anything solid. At the moment i have a ship which rotates at random as soon as i press left or right. I''m in a bit of a mess with the code i''ve created hehe. I''ll post the code i have if requested but promise not to laugh! Thanks in advance for any advice.