Welcome aboard Demonsss,
First you should find out what you are willing to mod accordingly to skills you've got.
Personnaly I don't have any major skill, but basic secondary skills that make me good at tweaking, but I don't think I will be able to do a great complex mod without any help.
By the way I play the Silent Hunter franchise since the first one, and I only started to mod the last month with the release of SH5 !
This began when I played the second mission in the first campaign when :
"What's the ... where is the depth under keel commands ? Huh ? And how do I order to return to the planned course ?? Grrrrr"
So instead of telling my navigator officer :
"Hey guy if you have nothing to do ... please do it anywhere else that on MY uboat !"
I started seeking in those script files and ended up to understand how the thing goes. And I added those missing commands by dialog to my navigator, so he won his place in my rig.
And then was born my first mod : the MCCD mod.
So again welcome and good luck in your creation, more heads and fingers will always be helpfull if we are willing to see a strong and talented team to make a GWX5 thingy ^^
