@muffindo, It's basic pc heli controls, i think if you google "bc2 heli controls" you'll find an answer quickly but i'll try to explain.
You use "w"to move the heli upwards, and "s" to move it downward, your mouse(or directional keys) tilt the heli forward or backward when moving your mouse forward/backward.
When you turn your mouse(or use the left/right directional keys) you rotate the heli left or right.
when you use "a" or "s" you tilt the heli left or right, this is usefull for evasive moves, but can make you crash when close to objects if you use it wrong.
My best advice is find a empty server running atacama desert, go engineer and if you crash just jump out before you hit the ground(the heli takes less damage from drops if it is empty) and repair. if you crash close to the enemy spawn andyour heli dies, grab theirs and continue practicing.
Parashute is the spacebar while you are in the air, you can use it anywhere very usefull to get off of high buildings. you are very visible with a shute out so deploy close to the ground.