Everything that is outside of the locked chests is available. You should have 8 sticker sheets of retired advisors. Use them as the rules state on page 20
Each player chooses a Retired Advisor to train one advisor they control with a new or better expertise. Each province must choose a different retired advisor. You must train an advisor if you can. If you do not have any advisors with empty slots, do not select a retired advisor and skip this step.