Mid September, u can go to Goa, great scenic beauty. u can catch a flight to Goa via Mumbai or train to Mumbai then from Mumbai to Goa Jan satabdi very scenic views u will get if u take this train, then go to South Goa amazing beaches other North Goa beaches, baga, calangute, Anjum u can enjoy they are good as well.
You can get all types of hotels there. It would be better if you stay in some homestay, as it would be cheap and also be very much fun. As you are planning to go there in July, so you can get hotels and homestay at a very cheap price because it's not the season. It would be better if you stay near the beach.
If you want to stay apart from a crowded area then you can stay in Vagator in North Goa and Arambol in South Goa. It's quite peaceful there.