DOT's Lesson Plans
Detailed guides on teaching K-5 topics
Sharing your screen and using a virtual whiteboard (the pre downloaded notes apps on Mac, Windows, iOS, and Android devices usually have some sort of drawing feature, you can also open a PowerPoint presentation and draw on that) is very helpful.
When using worksheets, take a screenshot or create a PDF and enter it into your notes doc so you can draw directly on the worksheet.
If you use online tools such as one of the MathApps, a PhET simulation, or whiteboard, play with it a little first before using it with students - only a minute or two would be sufficient!
Now that your tutee is relying on you to give them work, it may be a good idea to meet with them (and maybe a parent) and decide on a course of action - ask your student what they struggle with. Try to familiarize yourself with any CommonCore vocabulary (which is what your tutee will be familiar with) beforehand.
If you are unsure how to explain a particular concept, visit Khan Academy and watch how Sal Khan teaches it