So I am a new player of D&D and am making my character. I am not sure how to get the numbers for abilities: (wisdom, strength,..etc).

I read the manual and it did not go into detail about how to get these numbers. I have also looked online and it talks about rolling 4d6 and removing the bottom one but the numbers I have seen are like 1's, 2's or in the negatives when you do the method listed above you get way bigger numbers.

I might just be missing something obvious but I really need help. This is for 5e if you are wondering. I don't really know what I can do to make this more specific as I do not know much about this game.

The character is a half elf, Bard and my background is Outlander if that matters.