Text format on Carbonize 1.0.5

Hi. I find WordPress templates really confusing. So this is why I need help. lol
I have this template here called Carbonize. And as you may see from it’s preview or my website, the posts have a strange formatting. It’s really claustrophobic and I like things to look spacious.

Can anyone help me find where this is coming from, and how (and to what) I should change said tag to?

Thanks ??