is a card with 3080 in the description "better" than 3070? And 3070 "better" than 3060, so on and so forth?
Exactly - and this is true for both, NVidia and AMD cards. Then, if the card has suffiy like "ti" for NVidia or "XT" for AMD it's faster than the non-suffix version but slower than the next higher number (3070ti is faster than 3070 but slower than 3080).
Please get a least a NVIDIA 3060 TI
As AMD cards of the same performance class are still somewhat less expensive as their NVidia counterparts - how well do AMD cards in Aerofly FS? I would expect with Vulkan they should do fine but perform significantly slower with OpenGL.
A Radeon 6600XT for example is, on the paper, just slightly slower than a Geforce 3060ti but significantly cheaper too.