These guys (beefsteak tomato plants) were transplanted outside two weeks ago, and aren't doing well. Their leaves are yellowed and brown. I'm not sure if they're getting too much sun or have a mold issue. Any help would be appreciated.
To me, it seems just an adaptation problem. Just wait. In general, try to put seedling outdoor few days to a week before to plant, and in half shadow position.
In any case, I see only one tomatoes plant, and few other plants (one from pumping family) which seems too close to your tomato plant. Now they should not give you problems, but in future both plants should get much bigger.