Just do not keep all eggs in one basket. That's one of the main rules you have to know, its the best to hold your bitcoins on multiple wallets so you can not lose them all at once by some hackers or something, its the best to do for your bitcoins.
I only use online wallets for my bitcoins.
You of course need multiple wallets for the security.
Also the online wallets are really easy as an example blockchain is very easy.
That sounds bad to me, you didn't have any other wallet like paper wallet or bitcoin client wallet?
Too risky put all your bitcoin in online wallet which they possibly have access on your privkey.
Store only small amount in online wallet to spend, and the rest i suggest to store in non-third party wallet.