Great advice already, so I’ll only add this-
I just sharpened my rip saw this morning, and all I needed was a triangle needle file. Depending if you want cross or rip cut, or just follow what the saw already has, will be the only difference. I match the file to the angle of the tooth and lightly file it until it is uniformly brightened. It takes a bit of time on longer saws, but is fairly easy to do.