Open your task manager and observe CPU RAM and HDD. If the HDD is pegged at 100% all the time. I think that is a clue. Open your Event Viewer and look for clues. There are tons of red errors in there even on a new computer so Google is your friend there to help you figure out what the real errors are in those log that are causing you trouble. Inspect the motherboard for swollen capacitors. Excessive dirt choking the fans? Time for a cleaning!
Deal with the next one at a time and try it.....
Power Supply getting flakey? You need to test it or swap it out for a known good PSU. A sudden bad RAM stick could be fixed just be powering down the machine, unplugging the computer. Holding in the power button for 10 seconds to drain excess charge in the motherboard. Remove the RAM then put it right back in again making sure it is clipped in good. This will sometimes fix RAM problems. If you want to test the RAM head over to Passmark software and grab Memtest (Free) and make a bootable USB. Allow the test to run for 4 passes. If you have a discrete graphics card maybe that could be swapped out for a known good card?
Sometimes it is time for a fresh rebuild of Windows. Backup your files, export your browser bookmarks, make note of your passwords and take inventory of programs that you will need to re-install. Google this> Microsoft Media Creation Tool and create bootable media that you can install Windows with. Before you start grab drives for your PC from Acer and put it on the same USB drive so you are prepared.
This is the kind of work I do day-to-day. If it all seems a little daunting then find a local computer shop that does free diagnosis or low cost diagnosis ...it just might be worth it since we have everything we need including a ton of experience.