They look like some kind of Mbuna, and young ones at that. The yellow stripey one in the front might be Bumblebee Mbuna, but I can't say for sure, it's very young looking. The second one doesn't have a good profile view, so it makes it a lot harder to tell what it is. You'll need plenty of rocks as hiding places, they get territorial about them, and can be very mean. Depending on the exact species, you'll want to move the plants, Mbuna like their greens.