Heya Rime-chan welcome!
I know the feeling well too, I used to cosplay tons back in the States... but once I got here I ended up not doing so for about an year and a half! (well, mainly cause I was busy with other stuff) but finding other buddies to cosplay with really helped me get back into the spirit recently
Making friends could be tough in a foreign country even if you do attend conventions and stuff, unlike conventions back in the states many people have their routine planned out- so meeting new people can be pretty tough on spot (not saying its impossible, just can be hard)
I find finding buddies online and meeting up or planning stuff together before going to an event super helpful. So no creepiness there
plus its easy to meet other people when stuff is organized.
I'm fortunate enough to be living in central Tokyo, I've gone to several events around the Tokyo the last year or so. So don't hesitate to ask anything!