There are dozens of references to “law” in the New Testament. Almost none of them are instructions to Christians. Often the law of rules and regulations that Jews were under is contrasted to what Christians are subject to. Some illustrations of this contrast:
Romans 3:27 Then what becomes of our boasting? It is excluded. By what kind of law? By a law of works? No, but by the law of faith.
Romans 8:2 For the law of the Spirit of life has set you free in Christ Jesus from the law of sin and death.
Hebrews 10:16 “This is the covenant that I will make with them after those days, declares the Lord: I will put my laws on their hearts, and write them on their minds,”
James 1:25 But the one who looks into the perfect law, the law of liberty, and perseveres, being no hearer who forgets but a doer who acts, he will be blessed in his doing.
It might be imagined that Jesus leaves us without law. However from one point of Jesus’s instructions are no less demanding than the laws Gods gave to Israel. For example:
Matthew 5:43-44 “You have heard that it was said, ‘You shall love your neighbor and hate your enemy.’ (44) But I say to you, Love your enemies and pray for those who persecute you,
Rather than abolishing law, Jesus demands that we love him and reflect that love in the way we think as well as in our actions. “Legalism” means not only avoidance of the need to obey petty rules, but also means that we cannot use loopholes to avoid being the kind of people that we know God wants us to be.
There are many instructions to Christians on how to behave. For example to believe the gospel and be baptised, to love our brother and sisters and even our enemies, and to avoid sin. But these are not normally called “laws”.