I like my best guy friend and he commented about how I’m so much more talkative through Snapchat than in real life

So I like one of my best guy friends and he is a senior in hs I’m two grades below him. We had a class or two together last year but this year we don’t have any, so he has been walking me and a couple of our other friends to class. He made a comment a few days ago about how I send paragraphs on Snapchat but in real life I barely talk. This is bc I’m nervous but I played it off like I was just tired because I only see him right after second period in the mornings

What do I do? Are there any good conversation starters you guys could suggest? Any way to not be as nervous around him? Ugh help please!!?!?!