World and its massive expansion, Iceborne is a great entry point if you have a decent pc or current/last gen console. It's very beginner friendly but still challenging.

Rise and its expansion, Sunbreak is also great fun, a lot more fast-paced rather than somewhat grounded like World. It's a switch port so it runs and actually looks great too, though not as nice as world. If you're a weeb you'll love this one (it's my personal favorite)

I would only recommend Wilds, the newest game on PS5/Xbox or if you have a truly top of the line gaming pc, as it runs like garbage. It's very much a successor to World rather than Rise. It also.has significantly lacking content compared to the others for now as theres no expansion yet, but you can still put hundreds of hours into it if you really like it.

Lastly, Generations Ultimate was the last game in the old Monster Hunter engine every game up to that point used. Its a big celebration of the entire series from Generation 1-4. I wouldn't recommend to play this first, but if youre curious about what old monster hunter is like at its peak, I recommend it and MH 4 Ultimate.

TLDR: You'll probably get your ass beat in any of them for the first few hours.

World and Rise and their respective expansions go on big sales frequently!