Go to Marketplace (Altcoin)
Then go to Bounties (Altcoin)

Please do click any bounty you may see and read the instructions their,
If you have more time then read around 5 to 10 threads of different bounties,
You will understand how does it work.
Don't forget to check this or have knowledge about this:
-spreadsheet (dates) deadlines of posting per week
-ERC20 or ethereum address
-board to create your post
-do's&dont's

Good luck buddy.