Hi Mark
We're locked in to Apple technology for everything technical except laptops which I prefer to be Windows based, the fact that an equivalent Apple Mac costs at least twice as much is also an important factor to me but only you can decide.
I prefer a largish screen so always buy 17" and my latest bought earlier this year is a Dell Inspiron with 10th generation i7 processor and is very fast, not one of the fastest gaming machines but like you that doesn't interest me.
If going for a PC rather than a Mac look for an i5, i7 or better and the latest generation you can find, must have a fast SSD hard drive to run the system and if possible an additional drive to store your data and that doesn't need to be SSD (mine has 125gb SSD plus a 1tb data drive), at least 8gb of RAM but 16gb would be even better.
Most of the other components will be similar across the range, look at how many USB ports and will they cope with what you use currently, does it have a DVD drive, many don't now and it that's important then you might need to buy an external drive if not built in. I bought mine on line from John Lewis because of heavy discount and an extra year warranty but that won't help you in Ozzieland
Macs are subject to similar components and follow the same rules but only you can decide which way to go and my advice would be set your maximum budget first and look for the best spec you can find within that price, not the best time to buy at the minute unfortunately due to the shortage of chips and lockdown high demand but still deals to be had. You'll find that there are distinct supporters on both sides of the fence and arguments aren't always rational from either.
All that said, if your current machine is old then anything you buy now will seem lightning fast by comparison.
Bob