My house is 1980s built, thin plaster walls, and brown carpets.

I got a couple of large holes in some walls. Some rooms wall paper are
falling off because of condensation. My family wants to glue the loose wall
paper back on, and then paint over the wall paper. I thought about stripping
all wall paper off and painting directly onto the plaster.

What's the best way about doing up the home? Is painting onto the plaster
okay? We're no home DIY professionals. Who should be sought out for?