I just built a new PC a few months ago, also upgrading from a 10+ year-old AMD Phenom II x4!
I’ve been loving the AMD Ryzen 5 3600 (6 cores, 12 threads). It’s tough to beat for the price and performance, but you could probably save a bit and go with the Ryzen 5 1600 for your use case. Furthermore, the AM4 socket will likely see some future processor support, so future CPU upgrades without replacing the mobo aren’t out of the question.
Some useful info here: https://www.cpubenchmark.net/cpu_value_available.html
Also, if you end up getting an M.2 NVME SSD, I’d recommend one with a DRAM cache.