A few things.
Don't worry because bitcoin payment
will be back soon, through Bitpay.
Once you've purchased bitcoin you're free to move it off of Coinbase as you please. It's your money, and it won't go anywhere (unless something seriously bad happens). You can get your own software wallet to keep it safe (or even a hardware wallet). You could also potentially convert those funds back to your currency but you'll probably be eating fees doing that. There's also the option of just leaving it on Coinbase, if you trust them (there are some
reasons not to). AFAIK Bitpay doesn't store your money. You'll have to keep it somewhere and send it to Bitpay to process payments. So you might want to do some research on bitcoin before that option comes back.
Also this is probably not the right forum for this.