6 weeks Japan- last minute tips?

Hi everyone!

I'm a 25 year old belgian guy, due to really cheap flight tickets I’ll be traveling to Japan for about 6 weeks (late April → early June).
It's all really last-minute so, I have a lot of things to figure out on short notice.
My plan is to spend the first 2 weeks in Tokyo taking a basic Japanese language course, and then travel around the country solo.

I had a few questions and would love some advice:

• Any recommendations for good (and reasonably priced) accommodations in Tokyo during a 2-week stay? (hostels, share houses, etc.)
• After Tokyo, what route would you recommend for a solo traveler? I’m open to a mix of cities, nature, hikes and some less touristy spots.
• What are some “must-see” places that are actually worth it (and not just overhyped)?
• Any tips for meeting other solo travelers in Japan? (hostels, apps, events, etc.)
• General tips or things you wish you knew before doing a similar trip?

I’d also like to balance some alone time with meeting new people, so any advice on that is very welcome.

Thanks a lot!