for ownership, for a user named bill,
chown -R bill:bill /home/bill
will change all files in /home/bill to be owned and grouped to bill. Depending on what's wrong
(who's the owner now), you might have to run it as root.
I'd try the chown first as you (not root) and if it succeeds, you're done. If it fails you should see
the list of files that are wrong, and you can investigate them before su-ing to root to fix them.
For permissions, similarly, chown -R ... can be used to recursively change permissions, but you
have to decide what permissions you want. For example, you probably want execute permissions
on your directories but not on all your files.