Potential virus

Hi

please forgive my lack of technical knowledge which will probably become evident below.

Something or someone has added messages into my calendar. All messages warn of a virus or lack of protection and danger alerts. All ask me to click on a link, which I haven’t done, as I’m sure this would be a scam.

My question is how do I get rid of the messages? As one passed then another is added to my calendar the following day. They are scheduled for every hour and I can’t delete them.

Any help/guidance would be appreciated