Just buy bitcoins 
, or try cloudmining (PB mining)
, or try cloudmining (PB mining)Buying them is always probably the easist way and holding them could give you rewards. I wouldn't bother with cloudmining. A lot of scams out there.
Is buying them through coinbase efficient?
If you are from US and are going to trade bitcoin occasionally only, Coinbase is a very good option.
But if you are going to do a lot of trading, it is better to use an exchange.