Congratulations on your pregnancy!
I had two 14 months apart, unplanned. It was fine.
They are and always have been close and best friends even now at 10 and 11.
I was newly living overseas so no support or friends, and Dh was away a lot for days at a time with work...
My tips, get really organised!
Sort house out early in pregnancy, declutter, make easy spaces for tidying quickly, baby gates everywhere and a big playpen in most used room. I had a BIG 7ft square playpen full of toys on a thick rug in sight of Tv for toddler, it was a lifesaver kept dog out and meant toddler was safe whilst l was looking after baby.
Plan a routine that suits you, imagine how you are going to live day to day and plan for it now.
I followed Gina Ford with first and she was a very easy baby sleeping through at 4 months that helped!
As l has a c-section l booked a weekly cleaner, made a list of what was needed and gave it to her beforehand, also booked daily dog walker for first 2 weeks.
I cooked a months worth of easy meals and froze them, started a weekly food order too.
Stockpile nappies/ washing powder/etc all essentials for a month so if any complications no need to go out!
Get easy hairstyle!!!!!
Seriously though, l found it much easier with a routine as two that close are at least at almost the same stage for naps /feeds etc.
As they get older they always have immediate playmate too...