2007 Macbook wifi connection problems

I use a 2007 black macbook running 10.5.8. When I start up my computer or wake it from sleep, the wifi takes forever to start up. It takes almost 2-3 minutes to sometimes find any wifi connections. Sometimes I can get it to connect to one using the "Join Other Networks" option, but, when I do, it takes a minute after I connect to it to be able to do anything with it. It still acts if it isn't on the internet or something.
With my luck it's probably something stupid I'm overlooking, but, any help would be greatly appreciated. Thank you all very much.

yep

Yea, I tried that and it's not seeming to help. I saw somewhere in another post for a different wifi problem that they changed the channel setting on the router. Do you think that would help? Not that I'd be able to do that well, being I work and live at the same place lol