I wouldn't go to Dubai as a solo traveller looking to party - it's not an easy place to meet other travellers, brunches are mainly socialisation spots for expat families and travellers tend to stick to the beaches - with a once a week blow out at a hotel. If you want to do glitzy though, it's definitely worth a visit with a friend, I am saying that as someone who is not a fan of "new" Dubai.
One of the most important things I learnt was it was better to meet other travellers when I was booking more budget-end accomodation. Lonely Planet Forums (if they are open again) are really great for coordinating with people before you travel, and it is always wise to book a group excursion early on so you can meet other people at your destination.
Bali and Thailand are both long haul destinations - I've enjoyed them both so I am not saying this to put you off, but how about a short-haul trip to start. Berlin, Amsterdam, Oslo, Tallinn, Barcelona would be my recommendations of a good mix of nightlife whilst getting to experience other cultures and meet other people (other than just drinking with other people). Doing a shorter trip lets you test run things - what to pack, what not to pack, whether you actually enjoy travelling, what works for you meeting people and what doesn't. I would also suggest this due to the pandemic situation at the moment.
For more long-haul trips I would add Viet Nam (as above), Cambodia, India (Kerala or Manali/Shimla), Laos, New York, San Francisco and Seattle in the States, and Vancouver in Canada.
Do remember when you are looking at costs you will need travel insurance and some countries use a hotel and an airport tax. You may need a visa for some places as well, and so do look into the cost of that, as well as the timings you need to actually get it into your passport.
Have you had a look at tours such as Con Tiki? I've never done one, but friends who like partying have and really enjoyed them when younger.