Are there any decent free learning resources for AI / ML? (in your learned opinion)

Topic-wise these seem decent:

https://roadmap.sh/mlops

https://roadmap.sh/ai-data-scientist

But it would be nice to hear from someone experienced on good learning paths / learning resources.

I'm not against paying for tutorials but these £1.5k courses are way out of my budget.

Edit: I've got 7 years programming experience but nothing in AI/ML and nothing in terms of Data Science / Statistics if relevant