I use Plausible Analytics which is a privacy-focused GDPR compliant analytics tool. Plausible helps me to see which pages my guests visit and there is no tracking or selling your data for advertisements. I cannot identify you in any way. If you would like to know what data I see, here is the public version of my blog's analytics.
I use ConvertKit for emails. It tracks how many people has seen the sign-up forms. But that's all. There is no data collected besides that, no location, no personal data.