Hello Monica!
Nice to (virtually) meet you. What would you like to know?
I always think the motto "carry half as many clothes and twice as much dosh as you think you'll need" applies here 😉 Don't tend to bother with travellers cheques, they're old-fashioned and not many banks use them (in my experience, don't know about Japan)
Socialising will be ok, everyone is in the same boat on their own.....
Be careful when packing, don't include any liquids in hand luggage.....
have I missed anything?