1/ coursera https://www.coursera.org/ The first website I used. I took a data science Specialization https://www.coursera.org/specializations/jhu-data-science and https://www.coursera.org/learn/bioinformatics
2/ edx https://www.edx.org/ I took this one first https://www.edx.org/professional-certificate/harvardx-data-analysis-for-life-sciences and https://www.edx.org/course/statistical-learning and recently some management classes
3/ udactiy https://www.udacity.com/ I took R courses, ggplot2,github and intro to ML
4/ udemy https://www.udemy.com/ I took several python courses there.
5/ MIT opencourseware https://ocw.mit.edu/ 1806 linear algebra and many others!
6/ harvard CS50 https://pll.harvard.edu/course/cs50-introduction-computer-science?delta=0
7/ youtube channel 3blue1brown https://www.youtube.com/channel/UCYO_jab_esuFRV4b17AJtAw blow you away with cristal clear explanations. I watched the linear algebra series
8/ Khan academy https://www.khanacademy.org/
9/ free code camp https://www.freecodecamp.org/
10/ Hubspot https://academy.hubspot.com/ this one is new to me
11/ EBML-EBI training https://www.ebi.ac.uk/training/online/ bioinformatics courses
12/ skillup https://www.simplilearn.com/skillup-free-online-courses this is new to me as well