I wouldn’t immediately jump to that conclusion. There are plenty of legitimate business opportunities that do not imply “taking money to promote products”. In-line advertising and properly disclosed free samples are standard operating procedure for the tech industry, but they are completely above board, and by themselves do not imply bias.
Nearly every content creator’s YouTube channel About page or website will have a similar line, somewhere.
Don’t bother with the cert if it’s not your job, but at least look into CCNA Routing and Switching. There are tons of courses available, both in person and online, as well as numerous YouTube videos on the subject.
See if your local library or community college has an adult education center that provides a course. At some point, you will need to learn subnetting, which is just math, but practice makes perfect, and your life is easier if you have it committed to memory.
Proper written work is still one of the most effective ways to do this.