People across the street would like to cross are property to go and paddle board in the lake. I want to make contract so as to protect our property

You want to grant an easement to the people across the street giving them (and their guests?) the right to cross a strip of your land for the purpose of reaching the lake.  Such an instriment would need to meet the formalities of a deed.  This is not uncommon, and any lawyer experienced in real estate transactions should be able to draw it up.  It would be customary, but not obligatory, to grant the easement not to the people across the street personally, but rather to the owners of the property across the street, so that the right could be passed on to succeeding owners of that property, and would be binding on succeeding owners of the property being crossed.  The easement will be recorded and appear on any title report.