Chapter 130

3 If you, O LORD, should mark iniquities, O Lord, who could stand? 4 But with you there is forgiveness, that you may be feared. [Psa 130:3-4 ESV]

This psalm is an individual prayer for mercy.  None can stand before God, none at all.  His mercy and forgiveness is the only hope.

All of these are labeled "A song of ascent".  Not sure what that means.  Themes seem to be that God protects, and that we lift our eyes to Him.

2021 - vs. 6, "...more than watchmen for the morning..."  This phrase is repeated.  In Hebrew, phonetically, it goes "shah-mer boo-ker, shah-mer boo-ker".  I suspect that standing guard on the city walls gets cold and lonely in the winter time, even in Jerusalem.  And they didn't have digital watches.  They just watched for the first rays of mornings, longed for them, so they could go home to bed.

From Wikipedia:

Many scholars believe the title indicates that these psalms were sung by worshipers as they ascended the road to Jerusalem to attend the three pilgrim festivals [2] (Deuteronomy 16:16). Others think they were sung by the Levite singers as they ascended the fifteen steps to minister at the Temple in Jerusalem.[3] One view says the Levites first sang the Songs at the dedication of Solomon's temple during the night of the fifteenth of Tishri 959 BC.[4] Another study suggests that they were composed for a celebration after Nehemiah's rebuilding of Jerusalem's walls in 445 BC.[5] Others consider that they may originally have been individual poems which were later collected together and given the title linking them to pilgrimage after the Babylonian captivity.[2]

So we have many ideas of what ascent may be about, but we have no certainty.