There are a couple places where you can find out how many times an article has been cited by other scholars:

Option 1: Scopus

Navigate to Scopus, which can be found under "S" in "Find a Database". From here all you need to do is search for the article in which you are interested. To the right of the search results, you can see the number of times the article has been cited. You can also analyze whole journals by clicking on the "Analyze Journal" link above the search box and searching for a journal.

Option 2: Google Scholar

Navigate to Google Scholar, which can be found under "G" in "Find a Database". Here you simply search for the article in which you are interested. Under the link, you can see the number of times the article has been cited.

Option 3: Clarivate's Journal Citation Reports

Clarivate's Journal Citation Reports (JCR) provides the number of times an articles has been cited, though it focuses on overall journal metrics. Individual article citations can be found using Clarivate's underlying Web of Science database. From Clarivate's Journal Citation Report search the title of the journal that the article is published in. Once the Journal report pulls up, you can find citable items (articles) under Journal Impact Factor contributing items that will list citation count.

Please note: these methods may not produce a complete list of all times an article is cited because each searches different databases and sources.