May someone who is great with computers, help me find the best antivirus program, for my HP Chromebook?

I had opened a few spam emails, I thought were from my phone company, just called, and a woman said to me, that this isn't from them. I can't get into my inbox to read emails, which I so need to do. My chromebook has been lagging a lot since this. I also know that on my chromebook, has protected stuff or something like that to protect my chromebook.

what do you think I need to do?

thanks for reading

May someone who is great with computers, help me find the best antivirus program, for my HP Chromebook?
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