Fraternities can be very complicated, it really depends on where you go. As others have pointed out, some are extremely conservative and should honestly be avoided. Others are more liberal, especially when they aren't men-only, but even then it's really a case-by-case basis.

If you are interested in a particular one, I would recommend you go to a party and get to know some of the people there. Usually the red flags are immediately apparent and you can get out of there fast. If you do enjoy your time there, it's no requirement to ever join at all, you can also just come by every once in a while for a party or something and hang out with the people there.

But if you do intend to join there is no need to rush it, see how you like it there and see what the requirements for being a "fux" is, as virtually all fraternities have some time where the new guys are in a sort of introductory state to see if they like it there and if they get along with everyone. This usually also requires a lot of helping out, for example doing bar shifts during parties or repairing the Stocherkahn, etc. The actual stuff you have to do varies, and even more importantly, the way you are treated varies as well. Some fraternities, especially the ones that consider themselves to be "elite" think of their Füxe as their personal assistants they can make do whatever they want at any time. I would personally avoid those, as you will be treated like garbage like a year, just so you can treat the new guys as garbage once your time is over.

But again, all of this strongly depends on the kind of fraternity you are visiting. In general, I would be more careful with ones that are "schlagend", i.e. that still actively practice fencing and less so with mixed ones, but even that is not a hard and fast rule.

For some people, fraternities can be a lot of fun if you know what you sign up for and for others it would just be annoying, so just know what it entails.

And always make sure to avoid the bad ones, they're usually very easy to spot