I bought my 2018 at 2 yrs old and 1500 miles (one little old lady owner etc). I had one service done a year later just to "buy" some reassurance of warranty etc.
I intend to keep the car so from year 4 onwards I have serviced it myself. FWIW I use Honda 0W20 engine oil and filters, but each to their own on this.
I wrangled with the CVT oil change question. Even at 4 yrs it had only done 8k miles. I decided to change the oil using a simple drain/refill process, not the double "flush" type change which some sources suggest which would more or less double the cost. I work on the basis that if the oil is basically still good, then changing "most" of it will keep it perfectly serviceable even if some of the old stuff remains. I intend to do this every 2 years, working on the principle that the cost (even for Honda's own HCF2 oil !!) is relatively small compared to all the other running costs.
I use the same principle for brake fluid and coolant, change it using the simple method so most of it is renewed and do it reasonably regularly such that the amount of old stuff in the system is always kept to a low level. This works well with coolant since most of the reason to change it is because the corrosion inhibitor pack gets used up, so renewing most of the coolant gets the protection levels back without all the hassle of flushing and draining heater circuits etc.
Just a note to anyone doing the CVT oil themselves. I watched some youtube stuff, some folk use an oil pump/syringe to fill the transmission from underneath. One chap showed that removing the airbox and an odd hose or 2 allows you access to the filler plug on the top, which makes filling very much easier. That was the method I used. I found it wasn't actually necessary to detach the small hoses/pipes he showed (possibly throttle body heater pipes, can't remember), they could simply (just) be moved aside enough. Search youtube.
Essential tip, make sure you can get the filler and level plugs out BEFORE you drain the oil.
