Answer 1

To work in any kind of job in software, you must know a lot of stuff in a lot of areas. check out job adverts on stack overflow, for example. The amount of requirements is ridiculous

In my job, which is an entry level job, I deal with the following technologies on almost a daily basis:

MySQL, PHP, HTML, JavaScript (i.e the basics)
REST APIs like PayPal, sage pay, Fresh desk, DynamoDB
virtual container software such as virtual box, vagrant and docker.
many different IPs like FTP, SMTP, SSH, SCP etc..

I develop new tools for our team all the time using Python. including notifications systems, UI tools and such.

If you're working on web applications, these are the kind of technologies you are expected to know.