I formerly registered in block trades in 2017 and I was hoping to buy a few right away but I need to wait for they to review my documentation in order to buy.
I also used BlockTrades a few times in the past, but I also noticed in the previous few days that it asks us to upload papers to trade.
Technically you can deposit various cryptocurrencies to Hive Engine, and sell them for Hive.
Currently I do not know any other way to buy Hive.