really no reason to buy a 250, but if you know anyone who dirt bike rides they may have a small bike you can practice on.
Do not get discouraged with guys who will hide behind a keyboard while telling you that you are stupid. Just consider the source.
now about gear
helmet, preferably a full face, and not a cheap unit
a set of Road race style cloves, RR gloves have full fingers and are reinforced on the palms and knuckles where it can wear through in a crash
Jeans are a minimum, reinforced riding jeans are better, as is leather. I ride in reinforced jeans
some form of shoes that covers the ankles, no need to have the ankles damaged
a jacket, cold weather and leather is best, that classic bikers jacket is well thought out to keep you warm and protected, more modern designs work great also. I hot weather they make flow through textile jackets, they have padding in the elbows, shoulders, a back brace, and have a fabric design that allows air to flow right through and the material is designed not to wear through in a wreck. They start around $150 and go up.
Remember there are only 2 types of riders, those that have slid and those that are going to slide. All riders fit in the are going to slide category, Beginners usually are not in the Have slid group, you have slid once already.
the reason I say that is protective gear is not a joke, it is the only reason a lot of us are still around. I have been down at speed a few times, one time went into the rear of a VW bug by way of that little rear window. Protective gear is why I walked away from that with a bleeding pinky, a few bruises and that is all.
Go out and have a blast on the bike but remember, do not ride above your comfort level no matter what the group is doing. It is your skin, do not let others tell you how to dress.
good luck