On this page of our guide to Doom Eternal you will find a detailed walkthrough of Sentinel Prime level.
Our campaign walkthrough only shows you how to complete the mission. Information about the secrets and collectibles are in separate chapters of our guide.
Walk straight ahead - along the way you'll find some Codex entries including a description of the planet's history and location you're heading to. Go to the elevator and use it to move down. Go ahead and watch the cutscenes. Listen to Khan Maykr monologues.
The path is very linear, but on the map you will find some secrets, such as Codex pages and an extra life. You'll finally get to the arena, where there are Pink Demons imprisoned in cages. Reach the elevator and watch a cutscene. After that you will have to confront a Gladiator - one of the bosses in Doom Eternal (check the next section of our guide for a detailed description of this boss fight).