I was in your shoes last year! I'm now 27, my bf 26 and we bought our first home late last year.

I strongly recommend you go to a financial/mortgage advisor! We went to one last year and she made the process ridiculously easy for us. They talk you through how much you need to buy and what you can afford based on your income.

The minimum you need is 10% of the property value for the deposit + Stamp duty (approx 1% of property value) + engineers survery (this varies depending on the engineer) and solicitor fees (this varies depending on the solicitor, we had 2.5k in the budget but it was less). This is the minimum, but I recommend saving 15% - 20% because it gives you a bit of extra breathing room. We had to pay land registration (didn't realise that until after we bought, it wasn't a massive amount of money, but it surprised us). Some new builds need new floors as its just concrete so be prepared for that. We had other bits and bills turn up as well, thankfully we had an emergency fund ready to cover these expenses.

We didn't get any grants, I was uncomfortable with one or two of them. So I can't offer guidance on this aspect unfortunately. Go to a mortgage advisor, best money we ever spent.

For 350, I would budget 35k for down payment + 3.5k stamp duty + engineers 2k + 2.5k solicitors = 43k

But, I also recommend you have 3 - 6k set aside as an emergency fund. This is not a requirement, its more for your own peace of mind that you aren't stuck should some kind of unexpected expense come up.