Beta readers come in lots of different forms, and authors have their own definitions of what makes one, but essentially, a beta reader is someone who reads your work before it is published and offers their opinion. I’ve used beta readers in many ways and have found them absolutely instrumental in my writing process.
If you want to write then just do it. You don’t need an English literature degree or a diploma in creative writing. There are many professional writers who have never taken a writing course in their life. Many flunked school or never had any support. Anna Todd started writing on her phone in the checkout queue at a supermarket. She was a 24 year old new mum, and worked to bring money by babysitting and working at a beauty counter. She’s now a millionaire.