How to change the extrusion distance from 14 mm in to 13 mm in history extrusion 1
Click in the input field for distance, and set it to 13.
…or if you prefer a more visual adjustment, just simply tap on the step header and use the canvas controls that re-appear.
Check the errors which need to be fixed, marked on the history tree. The later extrusions probably depended on this first one, and now became invalid.
As you start up the app, there’s a “Get started with Parametric” card on the home screen. It leads you to a page with many resources, including great, high-quality tutorials and example models that explain the basic concepts behind parametric modeling and how you can use these tools in Shapr3D. I strongly suggest checking those out and following them along, it’s a much more effective way to build the foundations you need to become productive than us trying to answer questions one-by-one, inevitably leaving you stuck for hours or days until we can help.