The most basic sewing machines have just a straight stitch. As a minor hobbyist, this is all I have (I have an ancient Singer sewing machine from an estate sale).

You can make most things with a straight stitch, but it isn’t the strongest stitch. Usually you sew the seams with a straight stitch then go over it with a zig zag stitch or an overlock stitch to make the seams and edges of the fabric lay prettier.

The strongest stitch is an overlock stitch (there are a few varieties).

So, if you want to be able to make professional looking stuff you should look for a machine with at least zig zag and some kind of overlock stitch (everything will have an adjustable straight stitch). Something with a button hole attachment would be helpful too as they take awhile to do by hand.

If you want to do zaney patches some people like to use fancier stitches to make the thread borders fun. There are a ridiculous amount of stitch types.

There was a Serger craze for awhile. Sergers basically do just an overlock stitch but there are a lot of patterns designed for them if you want a one trick pony that does seams faster.

As far as brands you want something you’ll be able to repair. A good approach might be to look for sewing machine repair shops in your area and ask them for brand recommendations. I’m not familiar enough with modern manufacturing to know which ones are well made.

If you buy a used one you want to make sure the wheel turns smoothly when you press the pedal and responds well to changes in pressure (faster or slower). Sewing machines have to be taken apart and oiled every once in awhile, so that’s what you’re checking for.

Oh! Also one concern is fabric weight. If you want to be able to sew thick material (like denim seams) make sure the machine has a heavy duty needle available for purchase. Making sure you can buy needles for the machine in general would be a good idea.