Ok! So here's the critic: Bala shark is a big no no. Take him back. Balas are a schooling fish (they need 6 of their own kind), get very large and are high energy. To properly care for them as adults you need 200+ gallons. They are not aquarium friendly. Vote "no" by getting refunded for him.
Tiger barbs are cool fish, but also need to be kept in a school (6 minimum of the same kind) or they will stress out. They are also notorious fin nippers, so watch your angelfish, he might get harassed.
Red-clawed crabs can do fine in freshwater for short periods but eventually need brackish water with iodine to molt properly. This will shorten their lifespan considerably if not taken care of. They also need access to land, and are not fully aquatic. Read more here.
Red Clawed Crab - Sesarma bidens
The last thing would be the pleco. What kind is it? Bristlenose, rubbernose, and a few other kinds of plecos will stay under 6 inches, however, common plecos grow
over a foot long (and IMO get very ugly
) They also will need to have driftwood for proper digestion and veggies to munch on or algae wafers.
I have no idea about red lobsters, but gourami are great community fish, and Angels are usually peacful though once in a while they can get territorial.
Hope this help you! Stocking is always hard as a beginner and I think you made a few mistakes, but keep trying we are here to help!