Hi chaundra208,
We appreciate you reaching out to us. We understand that you are experiencing issues using Touch ID to install apps from the App Store.
We’d like to gather additional details that may help us be in a better position to assist you.
Are you able to unlock your iPhone using Touch ID?
If yes, we recommend that you try the steps under the "Manage your Touch ID settings" section in the article below.
Use Touch ID on iPhone and iPad - Apple Support
If no, we recommend that you reach out to us here so we can take a closer look into the issue: Get Support
Take care!