I always give up meat on Fridays in Lent so this isn’t anything new for me
Then this year, you could give up fish as well on Fridays (if you normally eat fish) or choose to have a second vegetarian day in the week, or make Fridays a vegan day or choose from one of the "other" suggestions.
My church tradition doesn’t think that Lent is about “giving up things”
Then think of this challenge as a way of celebrating and enjoying all the non-meat foods that are available. Vegetarian food does not have to be noticeably penitiental!
Surely Sundays are not included in the Lenten fast so why have a meat-free church meal on a Sunday?
See above – meat-free food can be delicious and Sundays can be a good day for churches to eat communally. Don’t think of it as fasting, but as a celebration of other food - doing something differently and reflecting on why you are doing it.