Hello @valdirrama. Welcome to steemit.

Setting 30% payout is easy, just follow these steps.

When you are about to make a post, click on advanced settings which is below your screen.

After it loads, you'll see the question, 'who should receive any rewards?'.

Click on add account
Input the % (30%) and type in the account you wish to add, i.e @steemingcuration, then save.

I hope this was helpful.