45 minute naps at 8 weeks also isn't unusual, dont worry. Just make sure that you keep awake time short between naps so that baby doesn't get over tired.
When I mention baby staying in a light sleep because of being over tired, I mean over an extended period of time - like over the course of several days/weeks. So if baby has a nap 1h after waking in the morning (which is usual) and still doesn't get into a deep sleep, it's not because in that moment he isn't overtired, it more means that over the last 48h (or more) he's not had enough sleep.
Being overtired had significant effects on sleep quality, it's why reducing awake times when naps are short is very important.
As for resettling to lengthen naps, its a case of practicing. Certainly don't expect a resettle to work initially. The idea is that you always try to resettle but don't expect it to work. Very occassionally it will though. Then you keep trying and the times it's successful gets more frequent until most naps are resettled. Then you work on reducing the input needed to resettle until no help is needed and baby stays asleep without input.
Only then (when no input is needed to extend independent naps to 90 mins plus) would I move naps into something stationary. Until then, naps in something that moves allows for movement to extend the nap (or attempt to), which makes it easier to extend.
Non independent naps (ie naps on you) are much easier to extend but they will take your journey to independent sleep backwards. So baby will find it much harder to ultimately learn to nap independently (and even harder still to link sleep cycles independently) once used to sleeping on you. If you are working towards independent napping, then don't underestimate the amount of work and input needed to help baby learn that - it is much more labour intensive on your part than contact naps.