Why people don’t accept the truth is a great question, but one not easy to answer. There are many reasons for this. Probably the biggest reason is tradition. It’s really hard to accept that what you and your family believe is not true. Another related reason is pride. It takes a person of humility to admit the possibility of being wrong and the ability to unbiasedly reconsider their belief system. Another reason is peer-pressure, as you have already experienced. The closer you get to the truth, the further you get from the world. The feeling of isolation and being alone is more than many can take.
Another reason for this, it’s not meant for all to hear and understand the truth now. This was the reason Yahshua said He spoke in parables: “He answered and said unto them, Because it is given unto you to know the mysteries of the kingdom of heaven, but to them it is not given. For whosoever hath, to him shall be given, and he shall have more abundance: but whosoever hath not, from him shall be taken away even that he hath. Therefore speak I to them in parables: because they seeing see not; and hearing they hear not, neither do they understand. And in them is fulfilled the prophecy of Esaias, which saith, By hearing ye shall hear, and shall not understand; and seeing ye shall see, and shall not perceive: For this people’s heart is waxed gross, and their ears are dull of hearing, and their eyes they have closed; lest at any time they should see with their eyes and hear with their ears, and should understand with their heart, and should be converted and I should heal them,” Matthew 13:11-15.
Regarding what is required today, while we cannot provide an all-encompassing list of commandments, we believe that the Ten Commandments, all moral laws, and all laws of worship, including the Sabbaths and Feast days, are required today. Regarding laws that would not be required for believers, this would include certain civil laws, judicial laws, and sacrificial laws. For example, the Bible commands that we place a railing around our roof. Since Israel used their roofs as an extension of their living space, this made sense. However, this would not be practical for most modern homes.
If you have not already, I might suggest reviewing the below booklets. These would equip you with many answers to some of today’s arguments with the Sabbath and Name.