Teams with more points in the group stage advance to the next round. There are usually two teams, sometimes one. However, in some competitions, you can directly advance to the two teams, and then some teams with good grades can also advance to the third place. For example, there are 24 teams participating in a game, and it takes 16 teams to enter the next round. Then these 24 teams can be divided into 6 groups, and the top two teams in each group can advance directly, and the remaining 4 teams with the best scores can also advance to the 16, thus forming the 16.
If the points of the two teams in the group match are the same, it is generally to see who has won more games (the number of goals MINUS the number of goals conceded), and the one with more will rank first. Some games look at the winning-losing relationship with the same points, the winner ranks high, and some only look at the number of goals. All kinds of competitions are different.