Not really! I was in the same situation a few years back. I went in to the bike shop and said look I never rode before what should I start off with. They pointed to the 250r and I bought it.
Well, I am 6'0 tall and was about 200 then. It is a very short bike and although it is kinda fast because its a ninja, its actually the slowest ninja I believe and you will get sick of it fast like I did probably. It just made me feel like I was riding something shitty also when riding with my other friends. I traded mine in right away and ended up losing money and going with a Honda 929.
Go with at least a 600cc at least you wont look like your riding the tricycle when your with your friends, and will be able to at least keep up. I think the 250 is not the proper size for someone of your height. Im wondering if they recommend it because youll be back to spend more money in the near future...
Hopefully you can use a 250r or something similar just for the course and the test so you can see for yourself and it will be easier, but when your all licensed up and have been riding for a couple of weeks youll be so sick of that 250 you will regret buying it.