One thing I will say is that it’s very individual.
There’s two main questions you need to ponder.
What are my weaknesses\limiters\areas for improvement when it comes to fitness.
What kind of activities can help with these that
will be fun for me. Ie will actually do on a consistent basis.
There’s some good fitness info here on the forums and on the main website to pour over. Here’s some links. Give them a read and let us know what you come up with.