When I started researching to build my efoil, I had absolutely no knowledge of electronics/electrical wiring. I agree with @michion! Once you do some research, you will realize that it is not as complicated as it seems.
All you need electronics wise is a battery with balance charge or BMS (a lot to read about that), a controller (VESC or ESC), a remote with a receiver (maytech is not great but best option right now) and a motor unit (motor, mast clamp, prop, duct).
Like @Jezza said, if you can find a ready to use board, you could focus on building a 18650 battery pack which @Vincentbraillard made a detailed guide about. However, I suggest that you read extensively about the subject before playing with 18650 cells as batteries are very dangerous! Then all you have left to build/design is the motor unit. There is an excellent pre-built option called the FR motor system. That’s the same motor unit that Lift uses. Of course, it’s not cheap but it will save you a lot of complexity and trial and error and it is the best performing/most reliable solution.
It all comes down to how much you want to spend and how much time you have on your hand. Skills and knowledge can be easily acquired through the process. If you get your read time to over 24 hours, you’ll have a better understand of how complex or simple building an efoil can be