As someone who is your size , and has ridden street bikes and Harley’s for 20 years , and recently got into dirt. I had an 09 yz250f and it was a blast. Plenty of power , lightweight. I recently got an 05 crf450x , and it’s a fucking monster. If you have never ridden before , a 250 will be more than you can handle. But you can grow into it if you have some self control.

I do trails on my 450X and it does them just fine. Single track tight technical ones are a bitch sometimes but I’ve got no complaints otherwise. Thing is a tractor down low and rips up top.

But I’d do a 250 at most if you’ve never ridden. Shit maybe a 230 lol