The good thing is, unlike desktop Sims like XP11/MSFS, you don’t have to pay for one add-on at a time, the pro subscription will take care of everything.
Note that there are three servers, Casual Training and Expert, you will have to start off at Casual first and make your way up gradually by gaining landings, flight hours etc. (There are annoying trolls on Casual, so I don’t recommend flying at airports like EGLL KLAX every day until you reach Training. Besides, there’s a whole world to explore!)
Also I strongly recommend joining the Infinite Flight Community (IFC). Many Infinite Flight users here on AWW have an IFC account (including me) and it’s an established forum with over 5000 members. All sorts of events and group flights are posted there, so it’s a great advantage for people who are looking to fly with others.
Last but not least, happy flying!