Trying to improve art quality

Consider the following:-

1. A family arrives by train to a tourist place

2. They go by taxi to a hotel

3. They book a room

4. They are in the room booked.

Currently my drawing is

I want to improve.  In quality.  I hope DMAIC improves my art. Just as PDCA improved my cartoons. 

Actually I have planned two sets of same drawing.  DMA one set. And IC the other. But above is one-one set only. Above is just for feedback.

I want to be marketable in USA comic world. But I am hardly there. Will my drawing comic have great quality lines in them? Will I make it to top in the comic world? These are the questions I have in my mind. 

I asked Google AI a relevant question regarding the dreams that I have in art.

Google AI says if my characterization is strong, if my facial expressions are strong and if my backgrounds of comics are better then I can be successful like Archies, Richie Rich or Dennis the menace.