Hi Mary, congrats on your new house!
I'm in a similar position myself, as we recently bought a (second hand) 2 bed townhouse.
My first advice would be not to rush to buy all the staff straight away.
Of course you need a fridge, washing and cooking appliances quick, you can have a look at places like did.ie to get an idea of prices. I reckon it will cost 2.5K if you go for good enough models (fridge + oven + hob + extractor + washing machine).
It's probably easy to get a cheap basic bed. If you want something more specific, arm yourself with patience because of covid and bed suppliers having to get deliveries from the UK. We are 2 months in and still sleeping on an air mattress waiting for our bed.
Also the sofa is ordered but will take another 2 months.
Important not to get carried away with the biggest sofa just to find out a year later that it does not work out in the space and you need to sell it at a loss.
I would invest part of the money in building a good toolset. Get a drill, learn to hang blinds, etc. yourself. You can get the most basic stuff from ikea, etc. and make it quite cheap.
An ikea kitchen island will double as kitchen table and storage space
https://www.ikea.com/ie/en/cat/kitchen-islands-trolleys-10471/
I would also not bother with an interior designer, I think you would get more satisfaction out of building the place bit by bit by yourself and making it yours, rather than someone arranging it for you.
Even if it looks bare at the beginning, enjoy, it is yours to make it yourself
Edit: forgot to mention, will you both be working from home? you may want to invest in some good desks where you can adjust the height.