m.2 nvme slot

It's my first time buying a board with M.2 slots. I'm thinking of buying the MSI PRO B660M-A PLUS WIFI. - A friend told me using the 2 M.2 slots will affect the system performance. Is this true? - What about SATA ports can I use all 4 without losing performance?

If selecting an AMD - Ryzen 9 3900X Matisse 3.8GHz 12-Core AM4 Boxed Processor with Wraith Prism Cooler, for example, which motherboard choices support a 2TB M.2 NVMe Interface PCIe Gen 4 Internal Solid State Drive? In fact, I can't find in any motherboard specs where they differentiate between...