Acts 20:7 says nothing about worship, rest, or the Sabbath, let alone indicating it was a new commandment to worship on that day.
"Now on the first day of the week, when the disciples came together to break bread, Paul, ready to depart the next day, spoke to them and continued his message until midnight" (Acts 20:7).
We learn from this account that the first day of the week was when the disciples came together. The phrase "came together" is significant because it describes the assembling of Christians for worship. "For first of all, when you come together as a church ..." (I Corinthians 11:18). In fact, the Greek word behind our word "church" refers to an assembly. "So it was that for a whole year they assembled with the church and taught a great many people. And the disciples were first called Christians in Antioch" (Acts 11:26). The coming together as a church was for a purpose -- to worship God. "Therefore if the whole church comes together in one place ... Whenever you come together, each of you has a psalm, has a teaching, has a tongue, has a revelation, has an interpretation. Let all things be done for edification" (I Corinthians 14:23, 26).
In Acts 20:7 we learn that the purpose of the disciples coming together was to break bread. Paul also speaks of this, "Therefore, my brethren, when you come together to eat, wait for one another" (I Corinthians 11:33). Glancing back to I Corinthians 11:23-26 we learn that what was eaten was the Lord's Supper. "For I received from the Lord that which I also delivered to you: that the Lord Jesus on the same night in which He was betrayed took bread; and when He had given thanks, He broke it and said, "Take, eat; this is My body which is broken for you; do this in remembrance of Me." In the same manner He also took the cup after supper, saying, "This cup is the new covenant in My blood. This do, as often as you drink it, in remembrance of Me." For as often as you eat this bread and drink this cup, you proclaim the Lord's death till He comes" (I Corinthians 11:23-26). Notice that the first part of the Lord's supper was the breaking of bread.
The breaking of bread can refer to the Lord's Supper. "The cup of blessing which we bless, is it not the communion of the blood of Christ? The bread which we break, is it not the communion of the body of Christ?" (I Corinthians 10:16). In Acts 2:42, we can see that breaking of bread is listed along with other acts of worship. "And they continued steadfastly in the apostles' doctrine and fellowship, in the breaking of bread, and in prayers."
Therefore, even though the word "worship" is not directly used in Acts 20:7, we know that this was what happened in Troas because on the first day of the week the disciples came together to break bread.
This not the only act of worship that is connected with the first day of the week. We also know that contributions were commanded to be collected on the first day of the week. "On the first day of the week let each one of you lay something aside, storing up as he may prosper, that there be no collections when I come" (I Corinthians 16:2).
Yet, you argue that despite the clear example, there is no command to worship on the first day of the week. However, we are commanded to follow the example of the early disciples. "Therefore I urge you, imitate me" (I Corinthians 4:16). "Imitate me, just as I also imitate Christ" (I Corinthians 11:1). "Brethren, join in following my example, and note those who so walk, as you have us for a pattern." (Philippians 3:17). The brethren in Acts 20:7 serve as a pattern for how we should behave today.
You also state that there was no mention of a rest or Sabbath. This would seem obvious to me. The Sabbath was the seventh day of the week. The Christians in Troas were gathering together on the first day of the week. They are not the same. Nor would there be mention of a rest because resting was how the Israelites kept the Sabbath. Resting is not how Christians keep the Lord's Day.