Try not to worry about money OP - babies don't need very much and you can buy so much stuff second hand or from budget supermarkets these days.
For example you could do:
Moses basket/crib for baby to sleep in - second hand off eBay (buy a new mattress from Mothercare though)
Nappies, cotton wool and wipes - aldi or Asda do good cheap ones
A few packs of vests and babygrows - primark and Asda do nice cheap ones
A cot for when baby is bigger - ikea do cheap ones or I am sure you could get a second hand one off eBay. Make sure u buy a new mattress though.
A few toys/rattles/books - look in charity shops, church bazaars etc for these and just give them a good clean/wash when you get home.
If you bf you just need boobs for the first 6 months! If you end up FF you will need to buy a pack of bottles and some formula and a steriliser. You can probably buy a steam steriliser cheap off eBay too.
Car seat if you have a car.
Buggy off eBay.
Some sheets and blankets for the crib - primark or Asda again good for this.
And that's pretty much it!
Good luck and congratulations. What a blessing.