Where do I check if a 1 satoshi / byte fee will go through for a 3xxx address segwit transaction? Where can I go to see if I set a 1 satoshi / byte fee that it will go through in a bitcoin transaction when using a 3xxx segwit address?
You don't know whether a transaction will confirm in advance.

You can look at fee estimation built-in to wallet software, or analysis sites, but ultimately it is up to miners to include your transaction in a block. There is no guarantee whether they will - just be prepared to re-issue or replace the transaction if it doesn't.