Research libraries tend to have help pages that explain evaluating the credibility of journals. I'll link to the Emory Health Sciences Library page, since it has some credible steps that I'll paraphrase briefly:
- In what databases is the journal listed? (is it in the big databases for your field?)
- What is the publication history? (has it been around a long time? is it on a regular release schedule?)
- What is its review process? (peer reviewed? refereed? how long does review seem to take?)
- What is the journal's Impact Factor? (a measure of citation frequency)
Evaluating a journal with these questions require some expertise in your field, so you should do the work of answering those questions, and consult a research librarian or mentor if you have questions. In general, I'd see if I can find it in the main databases I use for research, if it keeps to a regular schedule (biyearly, quarterly, monthly), if you can find any clues to how long their review process takes, and so on.
You can also use tools in some databases to look up an article from the journal and see where it was cited. For instance, if you find an article in that journal, you can search for it on Google Scholar and see the number of times it has been cited with the search result. You can then see where the articles citing the journal are published - do you know those journals? Are they reputable?