You could get an external Hard Drive and make a copy of all your important photos & documents.
Or..
You could wait until you have a Hard Drive fail, come on here and ask if there is any way to recover your photos & documents, be told there basically isn't without spending a small fortune, and even then probably lose some, then get an external Hard Drive and make a copy of all your important photos & documents from then onwards, while lamenting the memories that are gone forever?
It's amazing how many people, despite advice, don't make back-up copies of photos etc until they lose them.
If you are dumping your old PC, you could (should!) take the Hard Drive out and put it in to a caddy, then use it as an external Hard Drive, then copy stuff on to the new computer. Caddies are a few quid.
External HD's are reasonable now. For example, 1TB for about £40
https://www.amazon.co.uk/Seagate-Expans ... 212&sr=8-1