I have learnt so much from this forum since I joined and I can boldly recommend this forum to anyone who wants to learn more about Bitcoin and cryptocurrency but then for the sake of further knowledge you can further explore the sites and platforms mentioned by OP but then the knowledge you get here is wholistic so you may choose not explore other platform and stick here and still be good.

I'm currently taking some courses on Udemy and Coursera so I have only but few spare time which I use to come here and explore to get more information on cryptocurrency, I'm hoping soon I will rank higher here and be able to start earning from the forum. I'm taking a course on software development and web development on Coursera and another digital marketing courses on Udemy, I'm hope to round up by December the I will set up a profile on Upwork and fivver so I could get a job there and probably start earning, this is a sneak peak into what I aim to achieve soon.