Information about packages for internet and calls can be found on the Telkomsel website https://www.telkomsel.com/en/
SimPATI Telkomsel Usage
Most tourists use SimPATI Telkomsel. It's best to activate it in the same store where you purchased it (just ask the salesperson).
How to Top Up Your Account
You can top up your account at the same stores (just give the salesperson your phone number and payment).