I am 54 and I want to make a will, I don’t have many assets and I want to have it notarized by 2 witnesses. Is it then valid?

Not necessarily.  Notarization is by a notary, not by the two witnesses, and should be of an attached self-proving affidavit (though the witnesses and person making the will must sign both this and the Will.) You may not even need a Will.  If you expect to leave less than a home, household goods and personal possessions worth no more than $60,000 and other personal property, such as bank accounts, worth $75,000 and do not have a Will, your heirs can file an Affidavit of Small Estate.  This costs only maybe half as much as probating (proving) a Will and does not require a court appearance.