Hello
Use manual aiming.
1) Go into training missions. Do them (with manual aiming FCS) at least 10 times each
2) Read as much stuff on this forum, about your Nation that you chose as BO. AFter that. Read it all again
3) Tactical advice, if you look very close at the gun 'guidelines', theres dots. Depending on nation, most guns angle at 39-45 degrees, so those are your 'zero' ranging markers. Fire a shot off, you will see where shells land. Thats your 'zero' - at that angle.
4) The trick is, to 'know your angles'. When ships are rushing you (ie charging at you), all the guns have various degrees that the guns must be lowered. Thats why most people are experts in 1-2 types of ship :)
5) After all the above, there are dozens of people in this game who would give a short in game teaching lesson of manual fire
Rgds
farmdogeu