There were many weaknesses that the Articles of Confederation held, one of the main weaknesses was the federal government did not hold the appropriate power to create and enforce laws on American citizens.
In order for the federal government to pass any important laws, they had to have approval of 9 out of 13 of the states. This was a huge problem as many of the states did not agree on everything, so no laws would really get passed that would benefit anyone.
The federal government also could not enforce laws upon citizens properly because all of the power was with the states, so a lot of the time citizens did not have to obey certain laws as they should.
When the United States Constitution was created, this was obviously resolved. This gave power to the federal government to pass and enforce laws on American citizens, but it is still regulated. The amendments in the U.S. Constitution help to keep the federal government in check and have it so they can not take away our basic rights.