Get a professional perm.
how do you make your hair very curly without using a curler?
There's many ways, these two worked best for me:
Braid many bits of hair and then straighten (or leave over night)
Curl sections with fingers, put up in aluminium foil and straighten (my personal favourite)
There are many youtube videos that show people curling without an iron. I suggest you search for them.
Without hot tools you can curl your hair but it take over night.Other hand by use flat iron you can curl your hair.
1) Twist curl section than cover fuel paper and use flat iron (my favorite)
2) In curling section hold with flat iron and band your hair.