help with internet set up

the Internet that i use is really weird. I live in the middle of nowhere in Alberta and the only Internet we could get is kinda crappy. its pretty different from most others. they didn't give me an Internet modem thing. they have this antenna that shoots to the tower to get our Internet. I use a mac and it an older one. i set up my mac to shoot the Internet around my house like an airport base. the Internet isn't very strong because the only thing i can do on the wii are the channels and not any online gaming. i don't know what to do? should i try to manually set it up or should i try wireless?all help is welcomed, thanks:)