I started writing an article and cannot finish it in one day. Is there a way to save it to work on it the next day or something? Please help!

Under your article, there are a bunch of buttons: "Cancel, “Publish”, “Preview”, “Show changes” and “Save draft”. 

Click the “Save draft” button to save your article as a draft.

The button will turn grey and the text will change to “Saved”, to indicate that all changes have been saved.

You can access your drafts whenever you want to edit them at  wikihow.com/Special:Drafts .

Since drafting an article can sometimes be buggy and you might lose all your hard work, you can publish the article and add the {{inuse}} tag to the beginning of the article in front of the introduction. This will place a notice to the article indicating that an editor has reserved it for themselves temporarily. When you’re done, simply remove a tag.

We have an article that covers the topic step-by-step:  wikihow.com/Mark-an-Article-As-Inuse-on-wikiHow