My .02c beyond these other excellent suggestions is to do a few things in parallel over the course of time.
Look up shortcuts that will help you to work faster, such as at first I was wishing there was a way to quickly change the preview display of any components, so as not to get lost in the forest of components. Relative to that the first thing I discovered was the hotkeys ctrl+q and ctrl+e toggle preview and enable, respectively, of one or many selected components, of course used in conjunction with window/box select in addition to shift+click. Then after that I also discovered the button at top of viewport that toggles visibility control to only selected objects, overriding ctrl+q. These tools greatly improved my speed. Additionally you can use windows snipper tool to grab images of component previews, save, then drag and drop the saved file into your canvas, to give visual cues as to what is where, as an improvement over scribble text labels.
The other thing I did that helped me come a long way so far was to watch many good tutorials on youtube and work along with many of them, not always easy to follow along, but using the arrow keys are helpful for repeated rewinding. A couple of very good youtubers to watch for this are “Rhino Grasshopper” and “Daniel Christev”, as they are also explaining in clear english, not just modeling set to music.
I’m pretty new, only a couple of weeks into my software evaluation period, but very happy to say that I did put into service a fairly complicated design of a 3D printed mount plate for a folding basket to my ebike, which normally I would do in Solidworks, but forced myself to create 100% of the geometry in grasshopper, though I did have to import into solidworks to do a final subtract boolean that I coudln’t get GH to do still very happy with my GH progress though!