In either case, a Creative Commons license will be applied to your work, either based on the journal's policies (for example, PLOS uses the CC BY license), or based on your choice. Learn more about these licenses below.
These tools with help you verify the credibility and publication practices of the open access journals in which you're interested.
The resources listed above will help, but you should also consider doing a lateral search: open another tab and Google the publisher. If nothing comes up other than their own website, that's a red flag.