What are some of the best skills to pick up via online learning, that is useful and useable even without a degree in it?

https://www.coursera.org/ is a great way to learn new things for free and at your own pace! Perhaps you can start with learning something you like and enjoy :) If not, IT, data analytics, social media, e-commerce are increasingly important in this covid world.

I would say Accounting and Storytelling.

Accounting helps you to better understand your classification of your finances. It also help you in the future if you are planning to start an invesment journey. Furthermore, it is super useful if you are planning to start your own business. I took this skillset back in secondary school and never regretted since then. It have certainly helped me through the years.

Storytelling is another important aspect in life. As a creative myself, I always value someone who can tell their story well. Stories are what connects people together, through a share memory, idea, or experiences. Good stories often convince people to take action or join their movement. Think of how startups got their funding through pitching, think of how you propose your idea to your boss, sometimes it may sound logical while some may sound too idealistic but all these adds up to become a word — story.

So yeap, these 2 skills are what I recommend.