Purchase contract for a piece of land - who should review it?

Hello dear construction experts,

I am planning to build a house soon and have (hopefully) found the right plot of land. It has already been reserved, a notary appointed, and I have received the purchase contract for review.

Since I cannot fully understand some points (or some points sound different than in the purchase contracts of former properties) and I am completely inexperienced in the field, I wanted to get advice on this.

The real estate agent told me that he will come by and go through the contract with me. But I cannot rely much on his explanations, since he is only interested in the signing of the contract?

In my internet research, I have read several times that the notary answers questions about the contract. Is that correct?

It is often recommended to go through the points with a lawyer, but it is not exactly specified "what" kind of lawyer that should be; more precisely: what area of law should the lawyer be specialized in? Construction law?
Can one estimate what a review of a purchase contract by the notary will cost?

Regards

All questions answered in one response - perfect!

Thank you