Olá!
Have you ever gotten scared when seeing these words in Portuguese?
PRA / PRO
Don't be, it's just an informal way of saying "para" (for/to).
The first one, "pra", can be only the preposition "para" contracted, or it can be a combination of preposition + article (para + a / para + o), where "a" is the article used for feminine nouns, like "casa" (house), "menina" (girl), "lua" (moon), etc., and "o" is the article used for masculine nouns, like "amor" (love), "computador" (computer), "menino" (boy), etc.
Check it out:
Eu trabalho pra (para) pagar minhas contas.
I work to pay my bills.
(Eu) Tenho uma surpresa pra (para) você!
I've got a surprise for you!
(Nós) Estamos indo pra (para a) casa da minha mãe.
We are going to my mother's house. / We are heading to my mom's.
(Eu) Comprei cordas novas pro (para o) meu violão.
I have bought new strings for my guitar.
* As for the parenthesized pronouns in the sentences above: usually, we can omit the pronouns by using only the conjugated verbs to indicate the person.
**Please remember: PRAS (para + as) / PROS (para + os) for plural nouns.
Feel free to ask me anything or to suggest a new topic! :)