Neither of those services are bitcoin wallets, they are equivalent to banks, and thy contro the private keys.
A wallet is a program like Bitcoin Core, Electrum or Mycelium, that generated key-pairs and uses them to keep bitcoins.
To store bitcoins, I would suggest using Electrum or Mycelium in combination with paper wallets in the following manner:
Use the paper wallets to receive coins, until the wallet hits a certain amount (50 or 100 m
BTC), than switch to a new paper wallet to receive coins.
To spend coins, use your desktop or mobile wallet, and sweep a paper wallet when funds are insufficient.
This way, you never have most of your coins on the hot wallet.
I have posted instructions for paper wallet generations:
https://bitcointalk.org/index.php?topic=1559277.msg17075677#msg17075677In your post, you mention linking your wallet to your credit card, I can't tell you much there due to my lack of knowledge, but it sounds like giving up control of the private keys.
If you don't have sole and complete control over the private keys, you don't have any bitcoin!If you want to buy bitcoins, make and account at an exchange, buy them, and immediately move them to paper wallets.
If you can't make an account at an exchange, you can buy coins from a street seller.
If you want help creating an account at an exchange, I can't help you with that.