backup

https://codex.www.ads-software.com/WordPress_Backups

Plugins:

https://www.ads-software.com/extend/plugins/search.php?q=backup

this is like chinese to me

Then you might want to hire someone to help you set up a backup — it’s really very important, not just for upgrading but always.

https://jobs.wordpress.net/

my hosting company says that they do a backup once a week. Is that good enough if for any reason my site crashes when I try to upgrade wordpress?

That’s up to you – if you trust them and possibly having to restore from a week ago, then that would be your choice.

my hosting company says that they do a backup once a week. Is that good enough if for any reason my site crashes when I try to upgrade wordpress?

Theoretically, maybe, but I consider myself ultimately responsible.

BackUpWordPress is a decent plugin I have used…
https://www.ads-software.com/extend/plugins/backupwordpress/

I also do an occasional “Export” at the Dashboard.