just play through the first part of the campaign and you will get the hang of it, also ofp has this thing called "fade" which causes the game to fade over time if you do not properly buy the game, so make sure the one you are downloading has fade removed. becareful using hacks too as there are quite a few anti-cheat programs & scripts, on most public servers you can probably get away with it, most big pub servers kick anyone who has modified files cheater or not. that includes addons too, they require a "clean ofp". you can also gain admin in any server is there is not admin present by voting yourself and telling others to vote for you aswell, to do this if i remember you use this command : #vote admin Playername. you should also learn how to write the following file types: script.sqs, function.sqf & description.ext files