Welcome to Steemit!
To be able to post on most of the communities and to participate in contests you need to be verified. I am sharing two posts with you that will help you with your Steemit journey.

https://steemit.com/hive-136998/@event-horizon/guidelines-for-newcomers-all-you-need-to-know-is-here

https://steemit.com/hive-172186/@cryptokannon/achievement-tasks-resources-and-materials-newcomers-retention

Best wishes!