I was in this situation back in spring of this year. I wanted to join kendo but I was nervous that I would stick out because I'm an adult and a beginner and everyone my age would be super good. I searched online and found the local club, it turns out that it's held in the gymnasium at the local high school so I contacted them and they told me to come for a trial lesson. It was really fun so I signed up as a member and I have been in the group for 7 months now. It is by far the coolest thing I have ever done and the progress I have been making with my body has been amazing; I'm so pleased with the results. There are members of all ages starting from elementary school up through elderly (kendo is interesting in that way). Luckily there is another member who started two weeks before me and he is only a few years older than me so I never felt like I stuck out as a beginner since I'm not the only one. But it doesn't really matter because the attitude has been that everyone wants to help me improve and correct my mistakes. It has been an overwhelmingly positive experience.

As for sticking out as a foreigner, I don't think that's something you have to worry about either. I'm treated no differently than anyone else in the club. Some of that may be my own attitude as I'm the type of person who often forgets that I look different until I see myself in a mirror. But once we put on our equipment it doesn't matter because everyone looks the same with full kendo gear on; the only way to tell each other apart is by the build of their body and the nametag that hangs on the front of their loin guard but I have a Japanese name so I don't stick out until I take off my helmet. But again, I'm treated the same as anyone else so it doesn't matter.

If you're willing to do something like karate, judo, kendo and probably kyudo (does that count?) then there is probably a club within your town. There might be other stuff in your area as well but those are all basically guaranteed. I would recommend trying to do it close to home though because you don't want to be traveling by train and carrying equipment around multiple times per week. In my opinion it's just setting yourself up to want to quit.