We can use several shortcuts to navigate around a project:

We can Find a class using ⌘O (macOS) / Ctrl+N (Windows/Linux).

We can move the caret to a method and use ⌘B (macOS) / Ctrl+B (Windows/Linux) to go to the declaration or usages.

We can also navigate backwards by using ⌘[ (macOS) / Ctrl+Alt+Left Arrow (Windows/Linux), or navigate forward: ⌘] (macOS) / Ctrl+Alt+Right Arrow (Windows/Linux).

Use ⌘⇧E (macOS) / Ctrl+Shift+E (Windows/Linux) to find Recent Locations.

Or find Last edited location with ⇧⌘⌫ (macOS) / Ctrl+Shift+Backspace (Windows/Linux).

Finally, we can find ⌘E (macOS) / Ctrl+E (Windows/Linux).