Regular maintenance should be checking the air pressure in your tires before every ride. Lube the chain periodically. With the period being whatever is appropriate for the lube you use. And cleaning your bike when it gets dirty. As well as visually inspect it every time you ride.

That's about it.

Everything else can be performed when it breaks or doesn't function properly. Though when you get a bike with disc brakes or switch to tubeless tires, there are a few other things to check or do a few times a year.