All the major tech companies have a real interest in investing in training people in all aspects of computing and technology, both their own workforce and people who aspire to work in tech more generally.
A huge number of training courses are available online, some free, some paid. Even the paid ones will normally give an open syllabus of what is covered in a particular course, allowing people to research the content themselves online, if they are unable to afford the cost of the course itself.
Below are listed the main tech companies, with links through to more details about some of the courses they offer.
Apple
Metta