IMO, the decision to play in the tournament should be based on "Do Unto Others".
Let's say, instead of golf, it was a company-hosted ski day. Some would encourage others, including beginners, to participate and hope to share with them the joy of skiing and the camaraderie. They might forgo steeps, trees, and moguls and spend their time on green and blue trails with less skilled skiers. If that's how you would feel, yes, you should play in the tournament.
For that same ski day, some others would hope their day didn't get impacted by lesser skiers -- you know, needing help, or falling down and having difficulty getting up, or creating longer lift lines, or expecting them to ski with them for a few runs. Those who would feel that way have no business participating in that golf tournament until their skills are equal to the other team members.
For the golf tournament, just be true to your heart and Do Unto Others.
If you decide to play in the tournament, you could prepare by focusing your practice on just a couple of aspects of your game. If putting or chipping or 100-yard distances are your strength, get even better at them. Make that the areas where you can really contribute. As a first-year golfer, you're not going to have the whole package. Focusing on your strengths will allow you to contribute more that day and also build your confidence as you expand the breadth of your golf skills.