As a mum of 9-month-old twins, my best advice is to accept help when people offer it because you will need it! Don't worry about being superwoman - there's no shame in needing time outs or help with housework, laundry etc.
Also, try to keep costs down where you can - I found second hand clothes and equipment were often like new and a fraction of the price which was important for us as we weren't sure if we'd have two of everything or not.
I also recommend finding parent groups online or in person - it's so helpful to connect with others who are going through the same thing - especially if they're due around the same time because you can lend/borrow/swap gear and toys etc. It's also nice to have some IRL friends going through the same struggles and triumphs!
Finally, stock up on easy meals that can be frozen - lasagnes, curries, anything that can be thrown in the oven from frozen because some days you just won't have the energy to cook - or even think about what's for dinner. Congratulations, it's such an exciting time!