Hello. You have not informed the treaty to which these questions relate, which makes it impossible for them to be answered accurately. However, I will try to help you in the best possible way.
A treaty is an agreement that involves several countries and has international legal application. The treaty aims to resolve an issue that involves several countries and it is to this issue and to the countries involved that this agreement is addressed.
For an agreement to be valid, it is necessary to have a meeting with representatives of several countries. These countries approve that treaty by signing it. The treaty becomes valid if most countries sign it. However, it will only start to be applied, on the date determined by him.