The skills in these tools are transferrable. The designs not so much. Basically There's a way of thinking about and solving problems in these tools which is common, same as solving things in programming languages is similar but different and maybe different names. Annotations, lambdas, record types, functors they all have different names in different languages and commas and parens are used differently but when you learn one you get better at learning others. Another analogy is that it's a lot easier to learn to ski or snowboard when you can do the other one already than when you can do neither (even if you feel worse cause you know you can do better).

The hard part is if you build real ip up in these things that you lose when you get rug pulled. Or have no way to backup. F360 let's you export more complicated formats. But they all let you make stls which are a pita to reverse int drawings but you can.

It took me 50 hours to learn solid works, my first tool so I could kinda make what I wanted. Inventor took 3 to get used to. F360 an hour. The cost goes down.

Pick one your friends are using and design things.

Try openscad if you're more of a mathematical mind. Try blender if your an artist. Those are different yet still you're making things.

If you mentioned what you wanted to make I can point you further. There's many options.