Hello 666wojtek666 and welcome to the forum.
Sounds fun what you want to do.
In any case you will need the GSC Utility to extract & pack the modified files. You can read more about how to use it here.
Now as to your questions.
how to make houses capacity bigger
I see 2 ways to do this.
1.) Find NRES.DAT and look for the line
UNITS/FARM 15 ( Changing this value will reset for all housing that has the line FARM in their .MD file)
2.) Find the .MD files for a house. (DAU.MD, DAL.MD,...~Dom:House) and look for the line ( or add )
MFARM 50 ( Changing this value will reset only for this particular house, and in case its not there and you add it, it will overwrite the default value from NRES.DAT)
how to add a starting resources position in the drop down menu when starting a game (hundreds, thousands, millions),
Please see here for information about this : http://cossacksworld.ucoz.co.uk/index/0-184
It's somewhere on that page, but its for mines, though its the same procedure for resources. Iif you have problems with it, let me know what exactly.
how to make squads bigger like 200 or 300 soldiers
Squads are defined by 3 files on Cossacks I:
- Nation.NDS [OFFICERS] section
- Nation.NDS [OFFICERS] section holds which units are to be created in the presence of which officers and which formation they can create.
- Orders.lst holds what form and how much soldiers are present in the formation
- ORD_GROUPS.lst holds the various formations available to the player for the NDS files.
Have a look at these files, they are pretty straight forward.
Let me know if you need more help.