It will be very hot and humid..carry sunscreen..advantage eveything will be cheap..stays on beach will not be available due to rains..book in advance..stay in north goa near calangute or candolim..hire a scooty or bike and roam around with google map
It will be pretty hot in June, take precautions to protect yourself from sun. Else you can have best time in goa.
Must visit places in North goa. There are lot many Beaches, Forts and Pubs. Baga Beach is great with Tito's and Shopping. You can try some adventurous sports as well like Scuba. Also on the way Goa you can visit Dandeli if you like nature and many water sports available here.
Oh! Don't forget to carry sunscreen. And don't travel in noon - it will be scorching heat. Well, solo trip in goa would be fun. Visit church, beach, fort. Anjuna, victoria & menderem beach is my fav. While street shopping don't forget to bargain. Visit baga beach at night.