Travelling for about two weeks in July


I have some free time and wish to travel solo for about 2 weeks in the beginning of July. I am based in northeastern US at the moment, and I am looking for suggestions as to where to go. I would like something that is not obscenely expensive, and can be affordable on a grad student budget. These are some of the very vague ideas that I was considering:

1. Spain + Morocco(?): Barcelona, Madrid, Seville, and if I have time, take the ferry to Morocco and visit Marrakesh and Fes.

2. Greece, mainland and some islands

3. Central/Eastern Europe: specifically, I would love to visit Czech Republic and Croatia

I want places that are very safe to visit with good public transportation, which is why I was thinking of places in Europe. I would also want places that are friendly towards budget travellers. I would mostly be staying in hostels/smaller AirBnB's rather than expensive hotels. It would be great if the people where I go are conversant in English, as I am not fluent in any other European language.

In terms of interests, I like interesting food, culture, and architecture (if I am visiting a city). I am also interested in scenic places and exploring nature. Nice weather would be a bonus.

I am open to suggestions from other continents as well if anybody has good suggestions for a safe and friendly place!