Hi started EASY at about 4weeks. I timed going out around naps so either making sure i was home or putting in the sling/car seat in time to fall to sleep. Sling naps are not independent, car seat naps aren't either as the movement is a prop, however it is important to balance LOs need with Mummy's needs. I won't say there weren't difficulties, there were, my LO soon decided he needed his own bed to sleep properly and as much as I could I made sure I was home for them, not always possible. A couple of months down the line he wouldn't sleep in his pram at all and this caused us some big problems because of appointments I could not avoid or work around. I wished then that I'd got him more used to sleeping in the pram so that I could provide him with a decent sleep opportunity away from home.
My advise would be to try to make at least one nap at home every day, the same nap every day because LOs form habits and one good nap at home will remain with them all the way up to dropping the nap. If they are independent and prop free for that nap and bed time you can work in more freedom for yourself and your family needs. For example my LO always had a long morning nap at home, his afternoon nap and CN were in the car (one on the way somewhere, the other on the way home). The afternoon nap wasn't as long as it ideally would have been so he did struggle with tiredness and needed a shorter A time before the CN. It didn't give me the sort of freedom I imagine you'd like to have going out and about, I was trapped in the car whilst he finished a sleep cycle, everything was planned around setting off at just the right time for his sleep needs, bit of a pain really, but I couldn't avoid going out so it's a way to work around it taking everyone's needs into account and doing your best.
If the thought of staying home all day every day to allow your LO to sleep is going to drive you nuts, or make you depressed, then you really must get out. A peaceful/happy/healthy mummy is more important than sleep training.