How to start teaching without going overboard?

So an old friend of mine told me today that they are going to start school in hopes of becoming a Network Engineer and asked if I would be willing to teach them some stuff....

I don't even know where to begin. A different fried of mine asked the same thing a couple years ago and I explained basics and gave them a Nework+ certification book to read through. That guy all but gave up as I"m guessing it was pretty daunting and I came to realize that I must be a lucky student in that I was able to learn on my own without an actual instructor.

The guy asking this time is sure to be more willing to put in the work so I'm not opposed to giving it a shot but not sure where to begin or what I should cover vs what I should wait and let him learn in school.

Thinking back to my humble beginnings, I started out with the same Net+ book I gave the last friend, read it as much as possible until my boss at the time started getting upset that I was doing more studying in my attempt to start my career instead of helping co-workers with their load after I had all of my work done. From there I started studying for CCNA. I was able to get my foot in the door at a large Telcom company as a help desk tech and then started working/training with their networking team. I got really lucky on my path as at this point I knew the basics but didn't do much on my own and wasn't very confident. I had worked with the team for months and was promised the next open position even though I had not yet completed my CCNA. Well of course the position opened, I applied and it was given to someone else who had completed their certification (go figure) so that upset me enough to look for a new job. Luck was a lady that night as I ended up getting a job as a Network Engineer at a small MSP just based of my knowledge and ability to demonstrate as I had still not finished the CCNA.

Knowing that most people won't get this lucky and will need all the degree's and certifications they can get to get into this field, I want to try and prepare my friend the best that I can but I don't want him to get overwhelmed and give up. I was thinking of starting off with basic concepts covered in the beginning of the Net+ after I gauge his current understanding of how a network works. OSI, IP addresses, subnet masks, NAT/PAT, routing protocols, etc.

If anyone here has experience with showing someone the ropes and could provide some suggestions I would appreciate it. One of my co-workers taught Net+ in school for years so I'll be bugging him for ideas but figured might as well see what this sub suggests as well.

Thanks!