Hello fitri-kidul and welcome to SteemIt! Here are some resources that I found to be very useful when first starting out:

The ultimate guide: https://steemit.com/steemit/@wingz/the-ultimate-visual-guide-to-using-the-steemit-site-with-full-explanations

Securing your account: https://steemit.com/steemit-guides/@pfunk/your-steem-account-is-worth-money-how-to-secure-it-with-a-new-owner-key-to-keep-it-yours-forever

How to use tags and why it’s important: https://steemit.com/steemit/@rok-sivante/the-top-3-reasons-to-tag-your-steemit-posts-a-simple-quick-strategy-for-long-term-profits-and-success

Tips on how to earn money on SteemIt: https://steemit.com/steem/@trevonjb/my-7-secrets-to-earning-big-as-a-steemit-newbie

How to cash out STEEM: https://steemit.com/steem/@alexc/now-you-ve-been-paid-in-steem-dollars-what-should-you-do