What are some ways I can learn to develop my skills in STEM fields?

Take an "always be learning" mindset, first off. STEM is growing and changing—it pays to get core skills in a particular field but also remain flexible and adaptable. I recommend also learning on Trailhead, Salesforce's free learning platform (https://trailhead.salesforce.com/en/home). The content is growing (faster than STEM, I'd argue), and you get hands-on learning. It spans skills in the Salesforce ecosystem, sure, but also on skills in coding, project management, design thinking, and more.

From my own experience, I can tell you: there are fewer and fewer challenges that you could have in these careers as a woman, and although they were classified as "men areas", this statement is no longer valid, now we can have positions of leadership and management in these fields given the skills and competencies that each one has demonstrated to have, I've been in my company for only 3 years and I'm already a leader in the development team for cellular networks. I think that if you do what you are passionate about and you are good at it, there is no challenge that will be different from the regular challenges of any new job: the learning curve, the growth within a company, the certifications if necessary for a position higher, etc.

I think the best way to develop skills is in the field, practicing. In STEM, like in anything else, if you are passionate about something do it. I've personally discovered skills I didn't know I had. As women we tend to underestimate ourselves or think we are not prepared enough for a role or something. Men think different, they go get the things done and learn on the job, we think we need to be prepared to do the job. Don't overthink, I wish I could say this to my younger self, if you see an opportunity take it and don't think you are not qualified. Obviously you need some experience or knowledge but most of the skills needed will be developed on the go.