HTML, CSS, SQL - SoloLearn
SoloLearn is a series of free apps that allows users to learn a variety of programming languages and concepts through short lessons, code challenges, and quizzes.
HTML, CSS, JavaScript - UDEMY
Udemy, Inc. is an American massive open online course (MOOC) provider aimed at professional adults and students to take courses largely as a means of improving job-related skills. Some courses generate credit toward technical certification.
Google Digital Garage Certification - The Fundamentals of Digital Marketing
The Digital Garage is a non-profit nationwide programme from Google delivering free digital skills training via an online learning platform.