Help me with travel itinerary

Im travelling japan from 29may to 9th june
In between i have already booked flight to osaka on 31st may to 5th june
I have seen so many videos and read so many articals and now im all confused what to do and what not to.
Help me pick out best locations according to weather.
Ill be travelling solo and i love going to beach and mountains. Thanks for all the help tokyo chepo