The Sims Mobile features over 10 types of tickets. Each additional ticket is related to the events occurring in the game. The tickets are granted for finishing events or missions. In order to obtain some of them, you'll need lots of patience. You can't buy them for the in-game currency, nor real money.
The Sims Mobile features three types of free tickets - home tickets, super home tickets, and special home tickets. They're used for buying stuff for your home. The home tickets can be obtained for participating hobby and career events. The remaining two are only available if you send your sim for a special event. The award is random there, though - there's a slight chance you'll get a ticket there.
Another currency in The Sims Mobile are the sim tickets - sim ticket, super sim ticket and luxe sim ticket. It allows you to purchase new clothes and hairstyles for your sim. In order to obtain these, you have to actively participate in parties and interact with others. You can get a lot for participating in events with other sims.
The heirloom tickets are for buying heirlooms. The heirlooms are unlocked with the traits of individual sims. These tickets are also divided into 3 categories - heirloom ticket, super heirloom ticket and luxe heirloom ticket. In order to get the first type, you need to participate in family events - such those related to raising children. The remaining types of tickets can be obtained for selling the heirlooms obtained with regular tickets.
You can spend the gems in Izzy's boutique. You will obtain the gems by completing daily activities and for stickers. As concerns the daily events - one of them consists in giving 3 stickers, for which you can get two gems. As far as the stickers are concerned, you get a report once every week with a summary of all stickers you got during the previous week - the amount of gems you get depends on the number of stickers.