Hi Donald_S, it’s great that you are being careful to attend Mass on Nov. 1, the Holy Day of Obligation.
Minor correction: Your thread title mentions “All Souls Day” but you are actually asking in the thread about “All Saints Day”.
Nov. 1, the Holy Day of Obligation, is actually called “All SAINTS Day” and is the day when we honor all the Saints who are already in Heaven.
Nov. 2 is the day we call “All SOULS day” and it is the day when we pray for the souls of those who are not yet in Heaven (such as souls in Purgatory). All SOULS day, Nov. 2, is not a holy day of obligation, although many Catholics like to go to church on that day especially to remember their deceased loved ones.
I know it’s a little confusing, but don’t mix up the two days, they are different

My mother would explain the difference to me every year when I was a child.