Hi @BadGirl2023
For brushes, it really depends on the style in which you like to paint. My favourite is Memileo Impasto Brushes because I like to mimic oil paint.
You’ll find tons of brushes in Brushes and Bundles - Krita Artists
To make a sketchbook, create a new post in sketchbook - Krita Artists and upload any image you made in Krita, That’s your sketchbook. Now when you have further images to add to it, hit the reply button and add the new Krita image.
(by the way, I moved your post out of the ‘introduce yourself’ thread as you’re asking support questions which would have taken the thread off topic)