I also enjoy learning!
Keep up the great attitude! Your desire to learn (and keep learning) can be your greatest strength as you continue life!
If I understand your question correctly, and you are in the 7th grade, and are wondering about physics, chemistry, astronomy, calculus, and geometry, then keep in mind that some subjects lay the foundation for others, and sometimes they all complement each other. Let me give you some examples.
Usually, the way most classes are taught these days, you will want to study algebra first before moving on to geometry. (Although historically, the opposite may have been true in ancient history -- regarding when these fields were developed. But that's a different story.) Algebra also sets the basic foundation for physics, chemistry, calculus, and parts of astronomy.
There's lots of astronomy you can do on your own today, simply by looking up at the sky and taking notice: looking at the constellations, the moon, and the positions of the visible planets (Mercury, Venus, Mars, Saturn, Jupiter). Additionally, with some simple tools such as binoculars or a telescope, you can do more. If you want to pursue astronomy even further, there's math, math, and more math that fits into astronomy (if you are interested in such things) as well as physics and chemistry too! All of the above fits into astronomy in some way or another.
From an historical point of view, physics, as we know it today, was at least partially inspired by astronomy. And calculus was inspired by physics (and ironically at about the same time, and developed by the same people: Isaac Newton and Gottfried Leibniz).
The point of all that is although you don't need calculus to study basic physics, it certainly helps. It actually makes the physics easier. But you can study both together; they go hand in hand.
Chemistry classes require mostly just algebra and some geometry. And yet it can be argued that the foundation of modern chemistry is 3-dimensional quantum mechanics, with a few approximations (what chemists call "electron clouds" or "electron orbitals" are actually what quantum physicists call "energy eigenstates" of atoms, more-or-less, with a few approximations). But you'll likely never learn it in that order. Chemistry is usually learned by most people without any knowledge of quantum mechanics. Just make sure keep your algebra skills sharp.
So everything fits together with tendrils of one subject holding up parts of the others. And there's enough information fill a lifetime of learning.
My advice is to take it one step at a time. Even though they all fit together somehow, don't expect to learn everything, all at once.
And
do keep up the good "I really enjoy learning" attitude. That alone will get you farther than anything else I've said here.
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