present perfect is by far the most complicated tense in English. We use it for several different things that are only loosely related. Present perfect continuous is much simpler.
The basic idea of present perfect is "mixing past and present". Something isn't completely in the past, and it isn't completely in the present. This can happen several different ways.
1. The fact can still change. If you ask me tomorrow, I might give you a different correct answer. This most often happens when I am counting things, or when I say a word like "never".
"It has rained 3 times today"=The day is not over, so this fact can still change. it might rain a fourth time today.
"It rained three times yesterday"= Yesterday is over. This fact will always be true. It is impossible for rain to happen a fourth time yesterday.
2. When you make a conclusion about the past based on evidence in the present.
"Look! The grass is wet! That means it has rained here recently."
3. When an action in the past still has a strong effect on the present.
"It has rained here recently, so the ground is still muddy. Be sure to wear boots instead of tennis shoes."
4. When you mention the past in order to explain the present, or make a conclusion about the present..
"Bob said that it would never rain again, but it has rained several times after he said that. That means that Bob is a liar."
Present perfect continuous is much easier. It is almost always used with "for" or "since" when we want to say how long an ongoing activity has been happening.
"I have been reading this book for a week, and I am still not finished."
"He has been sleeping since 8:00."
We occasionally use present perfect continuous in other ways, but don't worry about them now--they are much less common.
HOWEVER, there are a few verbs called "stative verbs," where nothing happens when you do them. Examples include be, seem, exist, have, own, like, love, hate, know, understand, look sound, smell taste, feel, etc.... For these verb