Realistically, your best bet is an individual endurance sport, like long distance running or cross country skiing. Triathlons might be an option. Cycling might be an option, but equipment might be expensive and that could be a barrier.

Aside from that, others have mentioned shooting sports and archery. Curling or bowling could be an option. These would take years to develop, but are things that you could still do in your thirties and forties.

If you have the finances, sport fishing would be an option. In the US there are televised competitions for bass fishing, requiring a relatively small boat, and fly fishing, which you do wearing waders. Not famous people, but still playing for prize money.

Darts, pool, golf, disc golf all can be options for older athletes.

If money is no barrier and you can buy your way in, sailing might be an option. My guess is that you would have to start a bit younger in motorsports, but actors like Patrick Dempsey and Keanu Reeves started late.

I hope this gives you some ideas. Try a few things, see what sticks.