Welcome to this forum! 
Have you maybe searched for other “Home screen“ topics? I can find several ones.
For example this one Feature request: Home screen with shortcuts to custom notebooks new note has many tips.
Could you maybe clarify what you mean by home screen? Android/iOS home with all your apps? Or something else? What OS are you using?
If you open the URL joplin://x-callback-url/openNotebook?notebook_id=abc123in any external app (try your browser) it will open that notebook in Joplin. Replace the notebook ID by the correct one of course. Please note that notebook IDs change when you export and reimport your data as JEX for example in a disaster recovery, thus they are not that durable.
Similarly to open a specific note: joplin://x-callback-url/openNote?id=abc123