Yes, Web Strategic Marketing can maintain your website even if it was designed by someone else, typically the actions below can be complete in a couple of hours monthly or bi-monthly.
Wordpress websites require regular maintenance to remain both functional and secure.
The Wordpress platform is updated on a regular basis and as soon as the platform is updated the design themes and operational plugins may have to be updated.
Additionally, the following should be included on your maintenance list:
Dead links
Database maintenance
Delete spam comments and old page/post revisions
Check site statistics
Resubmit sitemaps to Google Search console