How can i dye my hair white?

So I wanna dye my hair but I had a perm lke two months ago but it was a wack perm n it didn't work and before I got the perm I had dye my hair abrun brown (like a week before)so now Im debating on dyeing my hair white but I don't know if I want the half on white on just two lines on the side white. But I'm afraid my hair will fall off.please help n give me all the tips u guys have I'm trying to dye my hair on my own..