>>96109481 (OP)Owlbear Rodeo and Maptool are both free and solid, and they cover the basics (e.g. they have maps and tokens, and--depending on the system--even access to character sheets).
If you move into paid options Foundry is your next stop. It's fifty bucks up-front for a license but there's no subscription. Foundry has all the basic stuff, but also has a pretty wide selection of supported systems of various levels of automation. Some of these systems are fan-made, others are official, and how much they do for you really varies from system to system, from basic character sheet support to heavy automation. There's also a big enough modding community that you can usually wrestle Foundry into whatever configuraiton you're thinking of.
For your use-case, if you want simple and free, I'd go with Owlbear Rodeo. It's one of the free ones and has a very forgiving learning curve. Maptool is crunchier but also more complicated. Foundry I'd put between the two in terms of learning curve (although if you dive into modding your game it can get just about as complicated as you like), but it's also fifty dollars, which not everybody's willing to drop for a VTT.