You won't find an answer that satisfies you until you begin to "rightly divide the Word of Truth", as the Apostle Paul put it (2 Timothy 2:15).
I'll give you a major clue. All of the passages in the New Testament that seem to teach to observe the law (commandments, rules, rituals, or whatever form the law takes) are found in the gospels and in the books written by someone other than the Apostle Paul.
Galatians 2:6 But from those who seemed to be something—whatever they were, it makes no difference to me; God shows personal favoritism to no man—for those who seemed to be something added nothing to me. 7 But on the contrary, when they saw that the gospel for the uncircumcised had been committed to me, as the gospel for the circumcised was to Peter 8 (for He who worked effectively in Peter for the apostleship to the circumcised also worked effectively in me toward the Gentiles), 9 and when James, Peter, and John, who seemed to be pillars, perceived the grace that had been given to me, they gave me and Barnabas the right hand of fellowship, that we should go to the Gentiles and they to the circumcised.
Don't take my word for it. Read this thread! I haven't read any of it at all apart from your opening post and I can tell you in advance that those who want to tell you that you have to follow the rules will get their proof texts from anywhere and everywhere except Romans - Philemon and those who would teach you that it isn't at all about following rules can only get such teaching from Paul. As an example, to highlight the difference, I offer you the following two passages. The rest of the thread can be divided into groups with the following to passages as headers...
Romans 4:4 Now to him who works, the wages are not counted as grace but as debt. 5 But to him who does not work but believes on Him who justifies the ungodly, his faith is accounted for righteousness,
James 2:14 What does it profit, my brethren, if someone says he has faith but does not have works? Can faith save him?
17...faith by itself, if it does not have works, is dead.
24 You see then that a man is justified by works, and not by faith only.
Resting in Him,
Clete