How do I get my first job as a designer?

It can be really tough getting your foot in the door as a junior.
My advice is just keep trying.
Speak to friends and family and so some favour jobs to build experience of working with real clients.
Get on Upwork and start doing you own thing to.
On Upwork you’ll need to be prepared to work for very little in order to build up reviews and cred first.
My advice on this is quantity over quality.
Do lots of tiny small jobs, be honest in your proposal and say your new and looking for experience and reviews, and in exchange offer a much lower price than the competition.
Trade time for reviews.
Of course to get reviews you have to offer a great service.
This doesn’t mean being the best designer or developer,
It means being the best communicator, making sure your client has a good experience.
Of course you’ll want to provide a  good result too. But experience is as, or more, important.
One thing I like to do is go above and beyond.
If you quote for redesign of a homepage, do some design changes on the about page and let  them know you’ve thrown it in as a bonus extra 🙂
Then as your profile and success rate grows, you can start charging your worth and increase over time.