Coinbase is easy to get started with but not sure if they are still limiting transactions. It took me a good year to establish & ensure a smooth flow of bitcoin & I use 2 different sites-one to "buy from" where I store my coin (for purchases on LB) and one to purchase bitcoin. I transfer the bitcoin to my "buy from" site.
I try to keep several hundred dollars in bitcoin at my disposal because you never know when they are going to change the rules and try to block (online) purchases.
a lot if trial & error and I lost, at first, some coin. Now I make a little cash in addition to having the coin to make a purchase on LB. Best case scenario is make a buy and bitcoin makes a nice gain and you can make your purchase off your increase.
Hope this helps.