Virgin at waxing please help I'm a teen?

Hi, I'm a teen, and here's my issue, I've been shaving with razors since I was younger (11), but when I turned 14 and started shaving again, my legs bleeded, so I laid off that and just did my arms. I tried to do underarms (I used conditioner and foaming vice versa not all together but on seperate occassions) and it doesn't work, my underarm hair still show little black dots, and I need some help. I have thick hair (half Italian) and it grows dark and coarse. So please help, I can't afford those salon waxing prices.... I need to learn how to do it on my own at home. I also have sensitive skin.... I bought Veet wax strips, they don't really work, cause like I said I have coarse thick strong hair. So please help!!!