Once dc1 was 2yo she did 2 x 2.5 nursery sessions a week. Not much really, but it got her ready for 5 X morning sessions just before she turned 3. So, dc1 was in morning session nursery at a private nursery when dc3 was born. All 4 dcs have done this. When they were around 3.5 they went to a day or two of nursery til 3pm.
I went to lots of groups with newborn in sling. Lots and lots of groups! And after the nursery pick up at noon, we usually did a packed lunch at the park, even in winter. The amount of mess that saves you at lunchtime cannot be underestimated!
Tbh, toilet training was never That difficult. Dd4 has just got the hang of it this month. I made this mistake of trying to train her over summer, but I realised I couldn't do it with the other dcs around, so waited til September.
It is tricky, I have zilch family support, and not many friends I can rely on either, but we've managed. There are some brilliance hints and tips on this board, especially the sort related to school runs/getting ready/meal time that may help you. May be useful to implement them now. I speak as someone who really only got up-to-speed with these hints when dd1 started school (and heavily pregnant with dd4).
I must admit I feel I've not given all my dcs the time they deserve. I notice this now that I am at home alone with dd4, which I really love. I am listening to her when she talks, I am not engaging in diplomacy or firefighting! But, in return, they have their own little gang of friends - an instant party! Something that often happens, which is really cool, no matter where we are with our 4 dds, other little girls feel compelled to join us because they think something exciting is going on - a group of 4 dds together - it's an incredible thing to watch!