How am I going to learn what words mean if you don’t explain them or translate them to English?

You will acquire them the same way native speakers acquire most of the vocabulary in their first language. Research shows that most words we know are learned incidentally, by just encountering them in context when hearing or reading them. The same thing happens when learning a second language as an adult. If you are a beginner, you’ll first learn mostly concrete nouns related to physical objects and verbs related to physical actions, since these are the easiest words to understand when watching comprehensible input content for beginners. More abstract words, like grammatical connectors, will only become evident later, when you can see them used in sentences in which you already know most of the other words. Learning vocabulary without explanations or translation is not only possible, it’s necessary. There’s no other way you can get an intuitive understanding of when to use a word, how to use it, and the nuances in its meaning.