boy

"ya boi" is slang for "your boy", which is slang for "your friend". "better" is slang for "you better", which is slang for "you should". The sentence could be read as "You should pick up your friend on time". They are asking for a car ride at a certain time. The language means the speaker is using 'low informal' English.

在哪里你听还是看句子？哈哈