TL;DR
As you are young software tester that keeps project quality at all time, we will list tasks that could be assigned to you and are in context of quality related activities and release support activities. This tasks are aligned with Black Box Software Testing Foundations course (BBST) created by Rebecca Fiedler, Cem Kaner and James Bach.
Introduction
Aside from typical software testers tasks listed in previous post Typical Software Tester Tasks In Agile Project, you can get a task related to diverse set of quality-related and release-support activities.
Examples
You could get message about new feature that is informal, incomplete and has conflicting information
On testers slack channel (informal), you received a message about upcoming feature that was just deployed on environment (incomplete, where was deployed?). Feature is about data chat export for every user while you know that chat is available only to paying customers (contradictory).
Market investigation.
You are reading health magazine in your free time. You see an add for personal trainer app. You decided to give it a try because you are testing such an app at your job and you are interested in personal training domain because you hit gym three times a week.
New features or changed in existing ones.
This overlaps with typical tasks: learn new feature and updated feature, hunt for bugs using risk lists for new features, write tests and crete test data.
Feature “freeze”
As features stabilized, you can do security testing, load testing, longevity test, huge database test.
Release is near.
Run regression test, update risk list, help create release details.