Currency - How current is the material that your using? Typically, if you scroll down to the bottom of page you can see when it was last updated.
Relevancy - How relevant is the information you are using to your topic and the purpose of your paper? Remember the goal is to not necessarily use the first resource that you find but the one that is most relevant to the information you are trying to convey.
Authority - Who wrote the information you are using? What is their authority to write on that particular topic?
Accuracy - As most of us know by now, just because it is online does not make it true. Does the author use any citations so you can verify the information they are conveying.
Purpose - Most information serves some kind of purpose. Even your research essay seeks to inform readers about a particular topic or issue. You will choose to highlight some information and leave some information out. Be aware that this is also the case for other authors. Also many authors including organizations have pre-existing bias on a particular topic. For instance, an organization such as <https://www.worldwildlife.org/> will take a stance on an issue that is alignment with their organization's mission.
The extension of the URL that you are using can tell you a lot about the type of resource.