Back end devs spend most of their time working with server side languages and databases.
Databases could be traditional RDMS SQL systems (Microsoft, Oracle, MySQL, Postgres) or No-SQL (mongo, Cassandra, Dynamo).
All devs should be familiar with Git SCM (GitHub) for code management/sharing and the Linux Cli to navigate projects and install tools.
Most jobs are for full stack developers and some entry Jr Dev positions can be obtained after attending bootcamp programs or college. It's recommend to work on a few projects and have a portfolio website to show your skills and the code behind it.
Aaron recommends the following next steps:
I'd say that the most important skill you need to be a good web developer is the ability to learn new technologies. Web development is a very dynamic field and so you need to be constantly learning.
If you can convey ability to learn during interviews, backing it up with a portfolio , internships, volunteering or whatever else you can, you would be surprised of how many opportunities you'd find even with little experience.
Mabia recommends the following next steps:
Also, this course will give you hands-on experience with Industry-standard projects at the end of course completion.
This website also provides a decent amount of Youtube videos as well.
Once you are well versed with these, you don't need to write HTML and CSS to create your webpages,you have a framework like React, which can dynamically generate web pages for you.
Apart from this, have handy tools like VSCODE, Chrome developer tools and Postman.