How do i make gui?

How can i make gui for my topdown game?

At first, you need to create a new layer for your GUI then create objects and do some settings to make them act like behaviour.

GUI is a very very broad term, you will have to elaborate on that if you want help.

→ If you mean making a menu, there are various examples, just search for “menu”. Here is one for example.
→ If you mean an in-game overly, you probably want to put it on another layer since each layer has its own camera, allowing to not move the camera away from the UI while centering it on the player. If you adapt the resolution at runtime you may want to add the anchor behavior on those objects too to make them be resized and repositioned with resolution changes.

Here are some tutorial videos that may also help: