capitalized "MOD" generally means Ministry of Defence so its better jut to use a lower case "mod"
First of all you first want to decide what area you want to go into as picking all 3 of thous things (or any more) is way too much to take in all at once, although like me you can learn all that stuff over time, I started off with just mapping.
Pick the area your most interested in and go with it, if it really dosen't work out after sticking with it for a few months you might want to look into another area but try and stick with the first area you picked.
Mapping is the easiest thing to pick up as there is lots of detail tutorials for it now as per the link AFsoccer provided but this on its own shouldn't be your only reason for taking up mapping or w/e, you should do what you think you will be best at and you have the biggest intrastate in
