Japan – tips & advice / First Time / Solo Traveler

Hey everyone!
I’m heading to Japan solo next week! I’m a female traveler and was curious to hear from others who’ve been there alone — how was your experience in terms of safety and general vibe?

I’ll be staying in Tokyo, Osaka, Kyoto, and I’m really hoping to make some friends along the way (like I have on my past trips abroad!).

Also, any first-timer tips would be super appreciated!
Should I book my train/transfer from the airport to my accommodation in advance or just get it once I land?

Thanks in advance to anyone who shares their advice or experiences!