How to change how many pixel you can have in Photoshop when you draw?

I just encounter an isssue when i use photoshop to draw. When I draw something like this:

image-20240122113110127

I fell when i zoom it and try to draw the detail, there is not engough pixel to work on.

So I google it and find out how to change it. Here is the step:

Search for image size:

image-20240122113536151

I double it:

image-20240122113629987

Now this is better:

image-20240122113931025