My warm welcome to the forum
I'm glad to see you sharing some photos already.
They are very cute and I think you've captured them nicely.
#1 like Khol said, is a more formal portrait and i think this comes across mostly through your dog's posture as well as the simpler background.
#2 exhibits it's adorable little figure i find and your idea of shooting from a lower angle works well IMO. If the background could have been a bit less cluttered, this shot would have been even nicer
#3 is interesting too but i have to agree that a greater depth of field would have worked better.
Overall i like the shots
and your dog seems to like posing as well.
Maybe also try a looser crop around the subject for the next shots.
Thanks for sharing !