To obtain your official initial rating, you must play FOA-rated games with FOA-rated opponents. As soon as one of those games is a win or a draw, you must play 4 more FOA-rated games.
When you get your PRO-subscription and don’t have the Over-the-Board (OTB) rating, your rating on FIDE Online Arena will appear as "new". This shows to other players that you just joined, and it also indicates that you are still acquiring your official FOA rating recognized by FIDE.
It’s also very important to your opponents — when they play against you, their rating will not be dramatically impacted by a loss (or a win), but they will help you get a permanent status.
According to FIDE Regulations, you get your initial FOA Rating in any time controls only after you have to score at least 1 draw or a win, and play 4 more FOA rated games on the Arena.