No apology necessary we all have asked similar questions in the past.
There are many methods for getting a firing solution and seems like your getting them mixed up.
For a TDC/PK attack you input Speed, AoB and range/bearing into the TDC and send all to the position Keeper (PK) that is the set of dials on the left
On the bottom right of that panel is a button to turn on the PK. This will update the firing solution as the target moves so you can fire any time you have a good solution. With map contacts ON and if you have entered good data, looking at the attack map there will be a white X that will be right on or very close to the target and it will follow the target as it moves. If the X is off adjust your data till it's correct. As long as the X is on the target you can fire and should get a hit. You will want to be at a good AoB, something between 45° and 90°. I use 65 to 90°
OPEN THE TORPEDO DOORS FIRST, Q key.
Shooting using a lead angle is a different firing solution, constant bearing solutions. Dick O'Kane (90°), Cromwell (45°) vector analysis, any AoB.
You do not turn on the PK for any of them and with vector analysis you don't input any thing into the TDC unless you have used it for some other attack. These are zero gyro angle attacks so the torpedo shoots straight out the front and the lead angle is just that, you shoot when the target gets to that bearing angle.
The only stupid question is the one you
don't ask, so feel free to ask away.
With manual targeting it takes some practice but soon the light goes on and it gets very easy. Stick with it.
Magic