Hello,
For newbies, or those looking to improve / refresh their CSS / JS skills, Udemy has a sale today.
I bought these two courses for USD 11 each (around 90% discount). That's 22 USD for around 70 hours of training. Great content so far.
CSS - The Complete Guide 2020 (incl. Flexbox, Grid & Sass)
https://www.udemy.com/course/css-the...box-grid-sass/
JavaScript - The Complete Guide 2020 (Beginner + Advanced)
https://www.udemy.com/course/javascr...nner-advanced/
If you missed the sale, just type "Udemy discount coupons" in Google, and you will be able to find coupons to get 80-90% discounts, almost anytime.
There are also great courses about Artificial Intelligence and some more complex languages.
I am not that convinced by the Affiliate Marketing courses such as "Affiliate Marketing Advanced: Sell T-Shirts" 
Udemy has some solid courses.
Their countdown timer and 'xxx sale today only!' are also a great study for funnel design 
For those that are broke (or a tricksie affiliate who doesn't like to pay for anything), you can also always go to https://www.freecodecamp.org and follow along with all of that. Not neatly as packaged, but definitely solid content.