1989 Volvo 240 DL - belt squealing?

Hello!

I am completely new on here... I've read a couple threads in the past few months seeing if anything is relevant to my car. For a little background: I bought a terrible 240 on Craigslist (first car buying purchase - it was bad one) and I've been fixing it so it's safe to drive.

I've got a new problem that I am worried about. Or maybe it's two problems, who knows? The first is the temperature gauge. It hikes up to juuust below the red and stays there, but often only when I drive on a freeway (or a big hill, I live in Seattle, WA). It makes me nervous, but maybe it's not a problem as long as it doesn't go all the way into the red? Should I be worried that it's high?

The second is a squealing when I press on the gas. Sometimes this doesn't happen, but more often than not (at least this week) it has happened. Also, when I drove home yesterday (after freeway driving), there was a burning rubber smell when I parked. Maybe that is part of the belt wearing away?

Any thoughts would be helpful! I have not much money right now, and I know very little about cars, but I am willing to to learn and to try to fix some more simple things myself. I am a very beginning in all this (buying and working on cars).

Thank you!!