Also, is there an advantage to buying from a broker over buying on an exchange?
Thanks
Buying crypto from any broker you don't personally know is a risk too big to take when buy cryptocurrency. The best way to buy cryptocurrency is to buy on exchange and the safest place to keep your cryptocurrencies is your personal wallet which you're sure its security has not been compromised.
Possibly, if you can meet with them one on one them that would be good but you can only do that if you want to undermine your safety but you should always have it in the back of your mind that safety comes first as you do not know who you are going to deal with as you have not met with them before.
For storage or safety of your funds and assets, your self custodial wallet should be your end point to our own safety.