Hi fellow Brazilian! There's a great English dictionary that offers the pronunciation of the words. It's the Cambrigde Dictionary! Also, regarding those words I can give you a tip. Basically, "sheep" is an "i" sound that is longer, while "ship" is a short sound

There is a website called for forvo.com that has audio recordings of native English speakers saying every word. You can hear the sound of any word that you want, and practice it.

You can use google translate, which will correctly pronounce each word or sentence.

Hola Gustavo! You can watch anything that is in English and has English subtitles. (Netflix, YouTube etc.) You can pause each line and practice saying the line to yourself. Then you can play the video and hear how it actually sounds. Sometimes the subtitles aren't exact translations of the dialogue, but this would be a way to practice real, everyday English in context. As opposed to learning phrases that are out of context