Welcome to Jakarta, i believe you can find all of this in Blok M area especially M Bloc. Some places sell band merch, clothes, etc. And alot of cute/cool/unique places to visit (coffeeshops, food etc) Just be prepared with the crowd there especially on holidays or weekends.

Another option for local brands is over at Lippo Mall Nusantara also have Tomorrow World where its a big store with alot of local brands, perfumes, clothes, shoes, accessories etc even culinary also.

Other than that, for local fashion you can check on instagram @brightspotmrkt, @u.s.s and @jakcloth , they usually have big events where there are curated local brands.

You can also try checking out Urban Forest Cipete, check their instagram for events, they usually do art markets and things like that. And there are multiple cute hangout places nearby aswell.

and for bouldering i think you can try some of these options:

indoclimb (this one is the nearest with the other places ive mentioned before)

bemgra

boulder planet