You can set up alerts in Google Scholar on topics of interest.
To set up a search alert on a topic just search for it and then choose "create alert" and follow the instructions.
Additional options are available in the Advanced search. Find it under the "hamburger" menu icon.
You can also set alerts on any article for any new citations of that article. Just click on the Cited by link
Then Create alert on the list of citations.
You can also use Google Scholar to see who has cited your own research publications if you create a Profile in Google Scholar.