Hi my 2 are 25 months apart and baby is currently 9 months also breastfed so I think our experience is relatively recent.
a few things- if 2 year old has childcare currently then try and continue some of it( doesn’t have to be full time) this gives them continuity but also allows you solo time with baby.
if 2 year old isn’t potty trained consider doing so before baby number 2 is mobile. I found it easier as didn’t have to worry about potty or taking toddler to toilet knowing baby will still be safe in place I left her.
in the beginning particularly when no routine is present for baby, focus on keeping your toddlers routine and adapt baby to it.
i also encouraged napping in cot/ Moses basket for baby from the start so that nap times are time with my toddler. Contact napping would prevent this.
get the toddler involved in baby stuff eg pass you the nappies.
prepare yourself that initially you will be with baby more so and your partner (if you have one) is more present with the toddler. I found that quite a sudden harsh reality.
i will say it really is a wonderful age gap. Now baby has an established routine and it fits in with our life managing the two of them is okay. I do sync their nap (my toddler still sleeps a lot!) and that helps my sanity too.
just try and get help where you can as initially lack of sleep made me less tolerant with my toddler.
congratulations and good luck!!