Here's a breakdown of the differences between Coins, Power-ups, and Tickets.
You get Coins by winning matches, through Daily Spin, and as party rewards. You can also purchase coin packages in the shop. Coins are used to buy Power-ups and Playlists.
Power-ups can only be purchased with Coins, and can be used to:
1.) Shuffle playlists
2.) Remove 2 Wrong Songs
3.) Remove 2 Wrong Artists
4.) To add more Best Match opponents if you do not have VIP Status.
5.) To add Boosts (Speedster/XP Boost) to your Party Mode rounds
Tickets are used to play Parties and can be collected as Party rewards, through Daily Spin, and by watching video ads. You can also purchase Ticket packages in the shop.