I'd suggest a shallow bench underneath the window and flank the windows with a base cabinet on one side and a desk on the other. Then open book shelves above the base cabinet and desk. I can't tell what the dark wall is on the one end. The steps need to curve from the door to the wall. A smallish sofa would be great for viewing a flat screne TV and a square table and 3 chairs up against the dark wall would be a great place for puzzles and games. Put a pendant over the table.

Mohammad. I understand your program. You may be lost in the details at the moment. Please do follow and trust the advice given here by all these people. You are about to embark on a reasonably expensive journey. Get professional help with someone who you can sit down at a table and brainstorm with them your ideas and intentions. There are Architects and there are professional building designers who are members of the American Institute of Building Design (AIBD) who are well versed in projects such as yours. I personally love a design challenge. After 38 years designing homes and special use buildings I enjoy this type of challenge the most. I am in Ohio and may not be close to where you are but I am sure with a little investigation you will find the best design professional for you.

Unless you have a very beautiful garage door I would paint it a color that blends with the brick IMO they are all too much in your face as is I loved it when the garage was at the back of the house not front and center

@spacelush, thanks for your comment :)