Acid Tommy

It doesn't say anything about what's loading. Instead, it only shows random jokes, like "Herding Kerbal ground crews", "Pointing front end towards space"...stuff like that.

I'm using a 2015 MacBook Air with the latest version of OS X. No mods. I'm new to KSP and am not particularly computer savvy either, nor am I a gamer...so you may need to hold my hand through this. This is only my second time trying to start the game. Anyway, when I left click on the KSP icon, the loading screen appears and the loading bar stays at 50%. Any help is appreciated. Thanks.