The exposure looks off. The shutter speed seems way faster than necessary for the conditions. Before you do more pictures for people, get out and practice with just your camera and learn how to get proper exposures.
Work on learning how to meter a scene. I find that sometimes in shade with sun coming in from the background the meter may be trying to adjust for that light - you may need to learn how to meter where the subject is then reframe as needed. It would help to notice the background before getting the subjects set; I think it may have looked better without that lighter patch of sun because it makes for a somewhat visually distracting bright area in the composition (and might have been what at least partly messed up the exposure).
Describing the quality, grain is in the emulsion of the film, noise is digital. It seems like you need to become more familiar with these type aspects of photography and the appropriate terminology. This is going to need correction on the color/WB and brightness and maybe a bit of a crop to make it acceptable. Shooting digitally I find it's going to be better to make adjustments if needed later if shooting Raw.
You seem to have engaged the subjects nicely and gotten smiles and good expressions. They'll probably like the picture if you can get some corrections made to improve the technical quality.