He is describing how through music he wants to be the best he can be. He references being like a sponge, soaking things up in life.
He then says,“soaking up despite you”, meaning he is still soaking up life even though most others wouldn’t.

He is referencing how in his last line he wasn’t trying to be funny but rather being serious.
Then he goes on to say that those immature people, or “haters”, are keeping him in line; just like driving and the median keeping you in line.

He is describing that people are telling him he’s a good rapper, but then he’s thinking about those people and how they are being immature,“You sipping something strong, but no you should be sipping Danimals.”
Referencing how they are drinking alcohol but should be drinking a children’s drink called “Danimals” because of their immaturity.

He is describing that in order to be a popular musician you need to start at the bottom, and work your way to the top. Then metaphorically speaking, he says its like hiking, meaning that in order to hike you need to start at the bottom to be at the top of the mountain.

He is describing his confidence with his music saying he’s almost to his dream. Then someone asks,“Like, Zack what do you mean?” He then answers saying, “Rapping for thousands, like the stage life scene.” meaning touring and performing shows.

He is describing how half of the world won’t realize his musical talent and so they are described as being “lost”. He then describes how he thinks some are selfish, and others just care about love (“just breaking them hearts”).

He is describing how then it hits him that he needs to start going public with rapping, and then realizes that he wants to have lots of fans coming to his shows.

He is describing how the first thing that comes to mind when he wakes up is to walk around and rap.

He is describing waking up in the middle of the night feeling anxious, nervous, and restless.