If you don’t have a proper saw with the proper angle locator you’re not going to be cutting around any corners I’m afraid. If it’s just straight runs then maybe - though a hacksaw is used for cutting plastics and metals and not mdf/wood. Good luck though.
For inside corners you should scribe the end to the face of your skirting. Outside corners 45 degree cut and some mitre mate. Caulk then paint, no problems.
Go and buy a mitre block and a fine tooth saw, it'll still be cheeper then a carpenter and you get to keep them.
Oh, and a coping saw for cutting the inside corners, if you need them.
Be prepared for buying a house to take longer than you think. The alignment of planets that is finding a suitable home, price, condition, owner buying their next property can take a while.
And do not scrimp on the survey.
Patience is the most important quality. So easy to get carried away after a couple of viewings.
You are better doing as little as possible once you are in a house too. It can take a while to get a feel for a place after which you are better placed to furnish.
Obvs if kitchen and bathroom are required do that but try not to presuppose anything else.