Get an 'external hard drive." To back it up... aside from what you have on your computer itself.
Also, REGULARLY, back up your computer. In case it crashes or something.
I would get a Mac computer.
VERY easy to use, and good for pictures/video etc.
ALWAYS back up your computer.
Or there are online 'storage' back up, services.
Do a Google search on it.
It is then an "offsite" backup of your computer or files you want to back up.
This is how companies, back up their information as well.
It is secure.
But DO get an 'external hard-drive back up" for your computer. It is always good, to back up your computer, via 2 methods.
ie: on your computer itself. AND with an external hard-drive.
Or, you just put all your photos on a CD/DVD, loading it onto that, from your computer.
But CD's/DVD's, can degrade over time.
Thus, it is always good to just back-up your computer always, and also onto an external hard-drive.