FIFA Mobile is a free game with microtransactions. You can buy currency with real money and use it to acquire packs from the store and such. It also has a system called VIP. You can access it from the left panel. You will see an option saying VIP.
The VIP system allows you to unlock ranks with VIP points. These points are obtained from packs that are bought from the store with real money. There are different packs and bundles available. You will see the price in your local currency. VIP points are sold in packs of 200, 500, 1.000, 2.000, 5.000, and 10.000. There are also some time limited packs that contain other currency in addition to points. When you have enough points, you will unlock a VIP rank. As you can imagine, unlocking a rank yields some rewards. The first rank costs 500 points and regales you with an XP perk, 5.000 FIFA 19 coins, and 100 gems. The next rank costs more points and has better rewards. Currently, there are 20 VIP ranks. The last rank costs 20,000 points. The rewards include 135% coins perk, 125% XP perk, 250.000 coins, and 5.000 gems. You also get a VIP store pack that has a 96 OVR player. This is the highest reward but there are some really useful rewards from lower ranks. For example, rank 5 allows you to train players up to 90 OVR. The market perk that is received at level 10 lowers the market tax when selling players by 5%. You will also receive training XP from higher ranks and store packs that contain 88+ OVR players, coins, gems, and boosts.
This system may be called VIP but you can get the ranks as a free player. If you are in a league, you can get points from certain daily quests. These points are used to unlock ranks. There are players that have unlocked VIP rank 20 without buying points from the store. It’s not the fastest way but it’s free.