The five solas of the reformation are:
sola scriptura (Scripture Alone)
solus Christus (Christ Alone)
sola gratia (Grace Alone)
sola fide (Faith Alone)
soli Deo Gloria (The Glory of God Alone)
What these solas have taught the Christian church in the last 500 since the Reformation is that scripture alone is our final authority for faith and practice, we come to Christ alone as the only way to salvation by faith alone by grace alone to the glory of God alone.
The five solas might be a new thing to you, so here are some recommended resources:
Sermons from Joe Thorn:
Soli Deo Gloria
Faith Alone: The Doctrine of Justification by Thomas Schreiner
God's Glory Alone: The Majestic Heart of Christian Faith and Life by David VanDrunen
God's Word Alone: The Authority of Scripture by Matthew Barrett
Grace Alone: Salvation as a Gift of God by Carl Trueman
Christ Alone: The Uniqueness of Jesus as Savior by Stephen Wellum
For one week, Westminster Bookstore has all five books available in one single bundle on sale.