Catholics can marry non-Catholics. It's called a mixed marriage, and one has to have the permission of the local bishop who will give a permission if he thinks it won't mess up the faith of the Catholic party. We can marry any races in the world and nobody bats an eye (except for bigots but they don't count.) However, marriages of a Catholic & non-Catholic are scrutinized closely, and marriages with someone who's civilly divorced, of the same sex, under age, ordained a priest, impotent, etc., aren't possible. We're very cautious about who marries who but the reason I mention what is meant by 'mixed marriages" is a fairly racist older neighbor thought we weren't allowed to marry black folks. Not how it works, sorry racists.
"Unequally yoked" -- a phrase beloved of the Protestant faiths, likely because that is the way the King James Bible translated 2 Corinthians 6:14-- is not found in the traditional Douay-Rheims translation of the Bible, frequently used by Catholics. Instead we have "Bear not the yoke with unbelievers. For what participation hath justice with injustice? Or what fellowship hath light with darkness?" In the King James Bible the translation is of course: "Be ye not unequally yoked together with unbelievers: for what fellowship hath righteousness with unrighteousness? and what communion hath light with darkness?"
Similar translations but different implications with the first line--specifically in the tense. The DRV version is active:
(you) | bear not | yoke
\the \with
\unbelievers
Meanwhile the King James version is passive: now it's been awhile since I diagrammed one complex like this so bear with me.
ye | Be not yoked
\unequally \together \with
\unbelievers
So the part is included, just reads a little different. Here's the footnote from my old Haydock's Bible.
"Bear not the yoke together with unbelievers. He does not mean that they must wholly avoid their company, which could not be done, but not to have too intimate a friendship with them, not to marry with them, to avoid their vices."
So if our buddy Greatshield17 is out looking for friends and finds Christian or Catholic Christian girls, maybe even a few Jewish ones, he's probably in good shape. They can find common ground. If he finds unbelievers, pagans, Unitarians, Muslims, etc., they can have a casual friendship but it probably isn't going to go anywhere because religion is important to a lot of people & an argument about the hypostatic union doesn't suggest happy domesticity but rather the Plenary Council of Nicaea.
(up to him if he drinks at the bar or not.)
Catholics can drink though we are not to get drunk--it's OK to enjoy your drinks but don't lose your use of reason. Reason is so important--can't go anywhere without it.
Meeting someone at the bar--is that sexual? I'm pretty sure that they aren't going to be stripping off & getting to it right there on the bar. That'd be a little distracting for the rest of everybody. There's a major connotation in the culture with sexual stuff and bars but he's talking about specifically a pub, and that's usually going to be a quiet & laid-back place to go get a pint of his favorite ale or something. He's too much a gentleman to be that sort who cruises bars for hookups.
So I guess it would maybe work? Got to try & find out. It takes a long time to decide on marriage anyway--lots of ceremony involved, such as a preparation usually of about six months. All kinds of good things are worth waiting for and marriages are like that too. Considering Catholicism will not let you have contraceptives or get a divorce, you might as well take time to be very sure you want what is about to happen!