1. yoga mat = for calisthenics and other stuff. if you're not bench pressing, pushups are your bread for chest
2. pull up bar = this is so good you should even buy one for home even if you went to the gym. this is your butter for back
3. light resistance band = 10 to 15 bux, usually for prehab/stretches
i actually recommend getting a smaller DB, there are a ton of beneficial accessory lifts you can do (cuban rotations for shoulder cuff muscle).
look up eugen sandow for a classic bodybuilder who used light DBs and calisthenics. if you want to invest even more:
- Jump Rope: Boxers use these for a reason, you can use it for cardio, conditioning, warmup, or HIIT. never a bad buy.
- Kettlebells: since you don't have a rack/bar, you can invest in these and get wonderful ballistic/full body work out of it
-gym rings: hang em on your pullup bar, you'll mostly be stuck doing lower ring workouts, but those are good upper body workouts anyways.
muay thai guys do a ton of calisthenics/kettlebell, look up their physique to see if you like it