The examples of English tenses on the previous page give only the minimum knowledge. You should know all of them to effectively communicate. The only exception are Perfect Continuous tenses, which are rarely used in speech or writing.
Inexperienced learners often use Continuous tense for no reason. A good advice is to use Simple tenses unless you are sure you need to use Continuous or Perfect tense and you know how to use them.
There is nothing wrong about keeping your speech simple. When you want to use more complex construction of tenses, you should do so for a certain purpose. For example, if you want to show that one thing happened before another, then it is a good reason to use Present Perfect.
When talking about the past a definite time is mentioned — use Past Simple (I bought a new car yesterday). Use Present Perfect if the fact is more important, rather than the time (I have bought a new car)
When speaking about your intentions, you can use will, going to or Present Continuous.