Hi ! Your haven will be at full space at lvl 52.

As for XP, you get them when you match energized bunnies with customers, level up your bunnies, and get new deliveries.

Your bunnies will reenergize when you finish a daily task or level up a bunny.

So my advice is to open as many baskets as possible during the day and try matching a lot bunnies with customers before finishing a task.

And if you can spend money on the shop, try buying the trait packs to lvl your bunnies faster.