In addition to these answers, you should also know that the preterite and the present perfect mean the exact same thing. There's no distinction in German between something continuing to happen and already being completed.
Also, even in spoken language, you use preterite with some common verbs like wissen (wussten), denken (dachten), all modal verbs (wollen, müssen, dürfen...ect), sein (waren), and haben (hatten).
Also, I recommend that you pay some attention to German grammar. When I was a beginner, it was only after I knew grammar relatively well that I began to pick up vocabulary quickly because I could actually USE the new words if I knew how to.
Let me know if you have more questions.