I travelled to Bali last year and visited Ubud, Kuta, Seminyak.
Ubud was the best of the three - make sure to keep enough time in Ubud to get massages and to relax in the cafes. Ubud has beautiful cafes and delicious food. Do try the coconut ice cream there, it is very different from what you get in India and thailand. When in Kuta or Semiyak, keep a day to explore Nusa Penida. This is a hidden gem and the place is breathtakingly beautiful! If you are interested in trekking, you can trek down the Kelingking beach. It is a ardous trek, but the experience is worth the effort. The island does not have very good roads and infra so be prepared for a rough day out, but it's worth it. I actually have a video with all my Bali travel tips, you can check this out this video, i had uploaded on youtube some time back. https://www.youtube.com/watch?v=tCtjOTHTa-A&t=283s