Looking to get new bike, cant decide between 125 or 250f.

You don't add many details. If I was going to get a bike and have not owned many, I would get the 125. A lot cheaper to maintain
Easier to ride starting out. A used 250f might need a bunch of money in motor work sometime in the future.
A 125 has plenty of power for pretty much everyone.

I can tell you with a 100% assurance, go for the 125. I faced this same decision and I am glad I chose the 125. It has PLENTY of power to learn on and you should learn how to control and use all of that power before you move on to a 250. I couldn't tell you how many people I see get seriously hurt because they start out on or move onto a 250 with little experience.

Get the 125 because it's a great bike to develop your skills on. Ride it for a while then get the 250f. And height isn't a factor on a 125. But weight might be. But I knew a fat kid who weighed 225 and rode a 125.