NEED SOME HELP

Sorry to bother you with those things , but i'm totally new to this. I downloaded that sonic game but it plays in awful resolution. I don't know anything. I don't understand how to get better graphic and i don't get it with those .wad files. I'm confused here :S
I'm sure noone wanna spend a whole day explaining , so is there any good guide to help me ?

Thank you all , i'm looking forward for your help :)

first off its called a option menu. second type addfile (wad).wad

To put in WADs, type "addfile wadname.wad". For instance, if you wanted to add in scr_mysticrealm.wad, type in "addfile scr_mysticrealm.wad".

To change the screen resolution, go into video options.

thank you guyz. i also read in the forum for the application loader so im fine now :)