I’m back home on my day off today, and on top of that, I just landed my very first internship interview invite! I’m back home on my day off today, and on top of that, I just landed my very first internship interview!

the alliteration at the end of the sentence makes me a little dizzy. It's not wrong per se, but usually we'd focus on the interview part and not the invitation / scheduling part, so you can omit the last word there.

Fingers crossed Fingers crossed

I am not sure why Lang correct is treating this as a separate sentence, but it's correct when attached to the second part below lol.

I can tell my story tomorrow with ease and really own it. I can tell my story tomorrow with ease and really own it.

it's grammatically correct, but I think a native speaker is more likely to say something like this: "Fingers crossed I have good news to share with you all tomorrow."