For now, I think I should first start by promoting my own skills (programming/development) to see how capable I am in marketing.
you are looking for advice about that site, but you have not publicly published the address. you are hiding it for some reason, it seems like you are not confident enough about the quality of your work.
from the point of view of marketing, it is completely wrong. marketing means that you need to spread information and introduce people to what you offer.
Post here links to your website, you will certainly get more suggestions and pieces of advice.