First, it's great to know that more and more people like you and I are becoming increasingly aware of the existence and dangers of predatory, fake and bogus, journals, publishers and conferences going on around the world. To answer your question, I recommend you download and read this resource guide on how to spot predatory publishing outlets as well as conferences: https://files.eric.ed.gov/fulltext/ED579189.pdf
Hi Dmitry, this is a good question for someone just starting out.
See suggestions below.
(1) Every field has a number of professional associations. In Communication we have the ICA "International Communication Association" (www.icahdq.org) and NCA the "National Communication Association" in the U.S. (www.natcom.org). Professional associations are going to be credible organisations in general and will be a good place to connect with leaders in your field, ask questions, and learn more. I attended two very small conference when I was starting out and was there alone. It was not a lot of fun. Conversely, a regional or national conference is going to have more people there in your field, likely friends from graduate school, etc.
(2) Lists. Most organisations have electronic lists. In NCA we have CRTNET, a list that was started by a professional back in July 14, 1985, and as adopted by the professional association about ten years ago. CRTNET has thousands of subscribers and can be used for news, information, questions, research, etc.
(3) Send a message directly to some of the leaders in your field and ask them. In my experience, most people are pretty nice and would be happy to offer some advice. Just keep it brief and don't ask a lot when you do not yet have any relationship with them. Conversely, consider asking some of the professionals who you follow here or on Academia, who are successful and influential.
(4) Advisor or mentor. Historically you'd ask your advisor or mentor such questions, or they should have told you. But not everyone has someone who helps them sadly.
Attending and presenting research work in professional bodies or societies related to your field of study will not be a bad idea. For example I am in the real estate field and we have professional bodies such as American Real Estate Society (ARES), African Real Estate Society (AFRES), etc. Its been always wonderful attending such conferences