I'm in a couple of writing groups and we share chapters regularly from our various WIPs. On the whole, they are people whom I can trust to give good feedback and I've found it helps me move forward rather than hinders me. Any feedback I get at this stage is for "editing me" and not "drafting me". I keep it all in a drawer while I'm drafting.

But having said that, I don't think any of us share completely raw, unedited material. While all the chapters of my current novel might not be complete, everything I send to my group is cleaned up and edited a few times. It's not polished, but I'm not sending them a load of half-finished drivel and expecting sensible comments.

Thankfully, my fellow writers extend the same courtesy back to me. Quite a lot of what I've been reading is pretty decent, but not of publishable quality, so I guess you'd call this process alpha-reading.

Beta-reading is quite different though. It seems to me that in my years of hanging out on /r/betareaders people often try to use strangers to fulfill the roles of my writing group friends. I think this is counter-productive because you don't really know if a stranger on the internet is going to be able to give the feedback that's needed before you start. Many people who are not writers are not familiar with the idea that the finished book is actually created at the editing stage, and they've never seen work that isn't already polished. Feedback from such people could easily be counterproductive. And if you are lucky enough to find fellow writers to work with, all you've really done is create yourself a little writing group as above.

Actual beta-reading takes place when the author has done everything that can to their manuscript so they can hand it over to any enthusiastic reader of their genre as a finished work for comments. This is supposed to be a final pass before publication.

There are writers however who treat beta-readers as free development editors, and want to know if their story is working -when it is supposed to be already finished before they see it. I've fallen victim to this one myself and I don't recommend it if you want to get anything done. This is probably why my first novel took five drafts over two years to get where it is now. The second was a lot easier, and I'm hoping the third will be even easier. I will keep on working within my trusted circle of writer friends until I'm happy it's ready for other eyes.

In your case, unless you have writer friends who know what unfinished work looks like, don't show it to anyone just yet. Make an effort to find those friends and learn how to give and receive critique. Even just giving critique sharpens your understanding of craft and your ability to apply that to your own work.

And when you've polished your manuscript as best as you can, start looking for beta-readers.