In the Missal for every Mass there is a couple of pages that direct the priest as to what parts are to be present for that Mass. If it is a Tuesday and it is a feast that has a Gloria, the Missal will say so, and in such a case the Gloria is required to be said or sung.
In short, some days have Glorias and some don’t. For a “regular” daily Mass, ie a feria, these do not have Glorias. On such a day it would be wrong to have a Gloria.
But if it is like the Tuesday of Easter Week, or one of the days following Christmas, these days have Glorias even though they are week days because they are part of special seasons. This sounds complicated but if you look at the Missal it is very simple.