Notes

https://www.catholic.com/qa/avoid-working-on-sunday-if-you-can
"First, God bless you for working to fulfill your Sunday obligation by participating in the Saturday vigil Mass. However, whether you fulfill your Sunday obligation at the vigil Mass or on Sunday, there is still the issue of whether the work to be done on Sunday is necessary. In providing for yourself (and your family if you’re married), if you can avoid working on Sunday, you should. If you can’t, the Church understands and encourages you to look for opportunities with your employer to avoid working on Sunday."

https://www.catholic.com/qa/is-it-ok-to-work-on-sunday
"Rest from work is necessary. We know that even God himself rests: “he rested on the seventh day from all his work which he had done” (Gen. 2:2). In recognition of this, the Church obligates us to rest on the Lord’s day. The Code of Canon Law states, “On Sundays and other holy days of obligation, the faithful are obliged to participate in the Mass. Moreover, they are to abstain from those works and affairs which hinder the worship to be rendered to God, the joy proper to the Lord’s Day, or the suitable relaxation of mind and body” (CIC 1247). However, the Church also recognizes that legitimate reasons excuse from this obligation. The Catechism of the Catholic Church explains, “Family needs or important social service can legitimately excuse from the obligation of Sunday rest. The faithful should see to it that legitimate excuses do not lead to habits prejudicial to religion, family life, and health” (CCC 2185)."

"It is good that you are thinking about the implications of working on Sunday at this young age; most young people (even adults) don't think twice about it. Working on Sunday should be avoided unless it is necessary. As the Catechism reflects, it should be a day of rest and devotion to God. Some professions like police and emergency services need to work on Sundays, but if it can be avoided, it should. Working on Sundays just to make extra cash is breaking the Sabbath, but if your job requires it in order to keep the job, and no better work is available, and you need to work to pay your bills, then it is acceptable. You still have to make your Sabbath happen and honor God by going to Sunday Mass (even if it is a Saturday Vigil Mass) and make sure when you do have a day off that you spend time with God as a priority. Our Lady of La Salette admonished the people because they were not keeping the Sabbath and were working on Sundays. They were simply trying to maximize their yield and had little concern for God's command. God punishes that kind of attitude and she warned them to repent. We need to heed that and remember God is the Lord of the Sabbath and our respect for Him comes first. That's why there is a commandment to that effect. So, when you are working out your schedule, make sure to advocate for yourself to fulfill your Sunday duties by going to Mass, honoring God through prayer and rest, and you will be okay, even if you have to work a shift on a Sunday. If you can't make Mass, then you can't take the job.
Peace,
Bob Kirby"