Have you heard of Massive Open Online Courses, or MOOCs? They are courses that you can take online, generally at no cost unless you want a certificate proving you completed it, which you can use to build your skill sets.
Skills you can learn through MOOCs include:
Also, MOOCs offer various career advancement courses in collaboration with tech industry leaders including Google (see Udacity), on topics like:
See the following pages for more information about MOOCs:
Coursera
Udemy
Udacity
EdX
Class Central
LinkedIn Learning
One way to learn and possibly get noticed by an employer is to participate in competitions and company-sponsored projects! Search on your own via Google and on platforms like LinkedIn, but you can also find some of them here: