can you get ball capsules on pokemon soul silver DS? and how?

Wow! That's actually a good question, the answer is not even on Bulbapedia!

This is the most reliable answer to your question that I have found:

"First you need the Seal Case, obtained from the girl on the left of the sick Miltank (You will need 7 Oran Berries to fully heal) and the girl on the Right of the Miltank will give you some Seals. From there you can go on the PC and re-arrange the seals and put the capsules on the Pokeballs. To obtain more seals you can go to the young girl in Olivine City, North-West of the Lighthouse in the house on the right, and she will give you three seals per day."

BTW how old are you? You left a big mystery there and Homo Sapiens Sapiens is a curious creature... (meaning: I'm curious now that you mentioned it)

to get pokeball capsules, you have to give Oran Berries to the middle Miltank in the Moomoo Milk farm. the twins will give you what you need to start; i think the one on the right gives you the ball capsules while the left will give you the sticker things. go into the pokemon center in Olivine and battle the Beauty beside the PC. she battles you (weak pokemon...) and gives you a couple letter-stickers.

look all over the two regions; you'll find what you need and a lot more!

hint: if you want to cheat, get a DS or DSi Action Replay; they only cost around $20 at Gamestop. Get a few codes on the AR and good luck!