Answer 1

The best field depends on you and where you want to work. You need to pick something you enjoy. Otherwise, you will be hating it after a few years. You need to pick something that has work available where you live or you might never get a job.
I could tell you here C++ for voicemail is the best because that is the only jobs available here. It doesn't help you, if your area only does Python. Read the local job listings to see what is available. Find what interests you and learn it.
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