Hi Chelles!
Thank you for your kind message, I'm glad that you enjoyed this silly game <3! I made this game for fun/not-profit/so everyone could have a chance to play it, so we're aligned on that value. Yes, you can definitely go ahead and translate the game dialogue. Thank you for your interest and labour in doing so (regardless of how far you get).
I would be happy to incorporate it into the game later if you do take the translation to the finish line, so other Brazilian Portuguese speakers can enjoy the game too, with full credit to you, of course. It seems that you already know your way around Renpy, but if there's anything else I can provide to facilitate your translation, please let me know!