If you want to take care of this cat first take it to be scanned for a microchip. Most any vet will do this for free.

If it’s unchipped or the owner has abandoned him/ her you can hold for 3 days to see if anyone comes forward. File a found report with ACCT. Then, if you’re keeping it- get it fixed asap. If not (and you’re concerned for his/ her safety) take them to ACCT for stray intake.