Your (e)sim card is already activated and you can use it right away. Change your SIM card no later than 1 August to prevent your SIM card from expiring. Please save your data before changing your (e)sim card. This will prevent you from unexpectedly losing data such as your contact list and voicemails.
Please note: Don't forget to bring your campus card or other identification when you pick up your (e)SIM card.