It’s a great photo technically speaking – you have nailed the lighting, depth of field and all that other stuff. However I would consider changing the angle to eye level or just slightly below. If the angle pointing up is too high you can distort the people. Overall a great shot for your first time!
I like it too. While you have to be careful about distorting people when shooting up at them, longer lenses keep distortion to a minimum. I don’t think they look distorted, so I don’t have a problem with the angle. A slightly different camera angle may have better shown they were up a tree?
I would prefer it if they were looking at the camera or looking at each other. A lot of shots like this look like they are looking at another photographer and you are just a second. It does look very technically sound though. Good job.