The Go Panel can be found in the Blender 3D View Sidebar. To open the Sidebar, go to the View menu > Sidebar. You can also use the Keyboard Shortcut ‘N.’

Once open, you will see buttons that relate to the modes of the Active Object. For example, if you have a Grease Pencil object selected, the buttons may look something like this:

The buttons are organized and labeled based on mode. All objects will have an Object Mode, but not all objects have special modes. The object types with special modes are:
- Armature
- Curve
- Metaball
- Lattice
- Surface
- Font
- Mesh
- Grease Pencil
Clicking on a button will switch your object into the mode and then switch to the tool specified by the button. For example, the Grease Pencil Fill Tool button will switch the selected Grease Pencil object to Paint Mode and activate the Fill Tool.
Keyboard Shortcuts
Go Panel buttons may be assigned Keyboard Shortcuts for those wishing to switch mode & tool with only one keyboard shortcut. This may be achieved by context-clicking (right-clicking) your desired button and choosing Assign Shortcut from the menu.

Note
If your selected object doesn’t have the mode specified in your Keyboard Shortcut (e.g. if you create a shortcut for the Grease Pencil Draw Tool and use the command on a Metaball object), you will see an Error Message.