Suggestion: Start basic, with article submit sites. Type "articel submit" in Google and you will get loads of sites where you can submit your article for free, and of readers like your article, they are able to put your article on their website (along with your name and url link).
After submitting your articles to these type of sites, try going one step higher. Do a keyword search for online magazines in your field and contact the editorial staff enquiring about the guidlines for submitting articles and the type of topics they are looking for.
You can also submit your articles to relevant websites in your field. Contact the owner or marketing director and enquire about doing an article exchange or just submitting your article to their site.