Welcome to steemit.
You may use up to 5 tags, each separated by a space. It is a good idea to have at least one image in every post. This way you won't be overlooked as easily.
Your introduction post is very important. People like to know in depth what you are like and what your interests are to know if they will enjoy following you. The introduceyourself tag and introduction tag are a great way to get visibility on your introductory post :)
I hope you enjoy your stay!