First marriage at 42....

After a long life of being a single mom, being successful, and not ever needing a man other than my Dad to help fix a sink; I am taking a leap with an amazing man whom I love dearly. We live in the house I bought in 2002 and as our wedding approaches we have been talking about prenups and wills. Of course we don't plan on divorcing yet in today's day and age anything can happen in the years to come.... We are both in agreement to a prenup however I am confused on what it should say... My children are in their 20s and obviously I want the majority of my assets to go to them. He doesn't own property yet I wouldn't want him to walk away with nothing if we did get divorced. Has anyone been through this or have any thoughts on what a prenup should entail with these circumstances?