Welcome Lilija. Actually it's not a requirement to prove your identity. Many users opt to remain anonymous on Steemit. I understand you had some misfortunes with hackers. So a piece of advice, keep in mind what you write on Steem is permanently recorded on the blockchain and you cannot edit your posts after the payout (7 days from posting). So don't use any personal or confidential information. Other than that, read the FAQ and have fun :)