What is the ideal score to buy a house at the most suitable T&C?

Well, there is no such "ideal credit score". But yes, you can take out a loan with suitable terms and conditions if you have a good credit score. A credit score of 700 and above is considered a good one! You can wait to build a good credit score and take out a loan afterwards.

Best credit score? Technically speaking, the best credit score is 850. Can you achieve that? Are you willing to wait until you get that perfect credit score?
Try to maintain a credit score between 700 and 750. That is enough. The credit score criterion for FHA home loan is much less.

If you can wait and you usually maintain a high score but your score has reduced for some reasons, you can wait to achieve the magical 800+ score. Usually, a mortgage lender locks the interest rate for about 30-60 days. I would say shop for loans and compare the terms and conditions so that you can take out the most suitable one.

There is no such number. However, if you have a good credit score, then you will be able to get a home loan with good term and interest.