They generally recommend you have at least 15 hours available per week, which I would say is a good guideline. If you can squeeze that amount out of the end of your day and weekend I think you will be fine.
Make use of the Slack channel and ask for help on your coding examples right away. It helps to be able to share code examples but first they want you to try on your own. The four projects require patience as I found I could never take it all in at one sitting.
Finally, I recommend you buy the course book Artificial Intelligence: A Modern Approach, 3rd Edition. I found a cheap copy here:
FAST SHIP - RUSSELL NORVIG 3e Artificial Intelligence: A Modern Approach T69www.ebay.com
I think you need to be able to read about the concepts they introduce because it’s a tough subject to tackle without knowing the “why” most of the time.
Hope this helps!