First-timers in Bali for birthday in mid-August before flying to Flores. How do we avoid the crowds and get beautiful, quiet beach time?

Hello!

My partner and I (early 30s) are Landing in Bali on 16th August evening after traveling to Java + Tanjung Puting for about 8 days, then flying on to Flores for 5-6days. We're first-timers and a bit spooked by the peak-season crowd/traffic/plastic stories. The plan is to skip Kuta/Canggu/Seminyak entirely and stay quiet- maybe a couple of nights in East or North Bali plus a few days on a Gili island for the beach. My birthday is on the 17th and I would love to be at beautiful and characterful places surrounded by nature. I don’t swim but like beaches. There’s no beach anywhere else on our 6.5 weeks trip across Thailand and Indonesia. (Instead there’s a mix of hiking in mountains, forests, villages etc plus day boat trip of Komodo Islands)

Questions:
Would East/North Bali be comparatively calmer than South in August, or are the crowds inescapable everywhere.

Are there nice beaches in Bali that fit the bill or should we go to Gili Islands / Lombok? (We have to fly to Ende/ Labuan Bajo out of Bali. I am also quite curious about the unique Balinese culture and Hindu temples.

Thanks so much