Starting something new is always a bit overwhelming. Let us help.
The quickest way to start is to create a new event...
First you will need an account. Have you created one yet? If so, head on over here to fill out the event details. You will need a name for the event like "Matt's awesome 3 on 3 basketball", and set a date and time.
You should optionally add a description to let your friends know stuff like where the event takes place, if they should arrive early to find a parking spot.
What ever you think it might help your friends meet you and have some fun.
Now all that's left is to start inviting your friends. You can either invite them by inputting some e-mail addresses or hit the share button and send them a link, so they can join you.