Hi @edgar8, welcome to the community!
1/ Test emails don't actually do anything with personalization as the personalization happens when the email is actually sent (not the test), so they always say <<FIRST NAME>>. However, on the next step in a new broadcast, there is a preview. In the preview, you can view it as if you are one of your subscribers (use the search to find a real subscriber) and that will turn it into their real name.
2/ You can change the font in the template. In the "Email templates" (found under your account settings), there is an option to change the font.