Regarding Sunday Worship:
Col 2
16Therefore do not let anyone judge you by what you eat or drink, or with regard to a religious festival, a New Moon celebration or a Sabbath day. 17These are a shadow of the things that were to come; the reality, however, is found in Christ.
Acts 20
7 And upon the first day of the week, when the disciples came together to break bread, Paul preached unto them, ready to depart on the morrow; and continued his speech until midnight.
Romans 14
5One man considers one day more sacred than another; another man considers every day alike. Each one should be fully convinced in his own mind. 6He who regards one day as special, does so to the Lord. He who eats meat, eats to the Lord, for he gives thanks to God; and he who abstains, does so to the Lord and gives thanks to God. 7For none of us lives to himself alone and none of us dies to himself alone. 8If we live, we live to the Lord; and if we die, we die to the Lord. So, whether we live or die, we belong to the Lord. 9For this very reason, Christ died and returned to life so that he might be the Lord of both the dead and the living. 10You, then, why do you judge your brother? Or why do you look down on your brother?
Gal 4
8Formerly, when you did not know God, you were slaves to those who by nature are not gods. 9But now that you know God—or rather are known by God—how is it that you are turning back to those weak and miserable principles? Do you wish to be enslaved by them all over again? 10You are observing special days and months and seasons and years! 11I fear for you, that somehow I have wasted my efforts on you.
St. Ignatius writing in about 105 AD:
Chapter 9. Let us live with Christ
If, therefore, those who were brought up in the ancient order of things have come to the possession of a new hope, no longer observing the Sabbath, but living in the observance of the Lord’s Day, on which also our life has sprung up again by Him and by His death— whom some deny, by which mystery we have obtained faith, and therefore endure, that we may be found the disciples of Jesus Christ, our only Master— how shall we be able to live apart from Him, whose disciples the prophets themselves in the Spirit did wait for Him as their Teacher? And therefore He whom they rightly waited for, having come, raised them from the dead.
newadvent.org/fathers/0105.htm