Here's the good news
If you are a native or fluent English speaker, you are already an intuitive grammar master. Our brains are wired to learn grammar from the moment we are born, and you’ve been learning English grammar all your life, or at least for many years.
In English at least, we pick up grammar in a surprisingly consistent order:
Around the age of one, we start to learn words for objects: dog, fish, cup, book. (But these aren’t always nouns: ‘woof’ might represent ‘dog’.)
Then we start to learn words for actions, usually as commands: up, drink, go, mine. Again, these aren’t necessarily verbs.
Then we start to learn hard-to-categorise but socially-useful words and phrases: bye bye, no more, where.
Even with these basic materials, little toddlers are learning some basic grammatical rules: that there are words for things, words for actions, and phrases that we don’t use to describe the world so much as interact with each other.
Soon we start to put these words together: where dog, my spoon, want ball.
Again there is some grammar there: for example, we are figuring out that question-word, describer-word, and action-word all come before the thing-word.
And then suddenly from that point things come together very quickly, and over a year or so we will start speaking in full sentences: I want to go to the toilet; when are we going to the park; I can’t find my bunny.
These are still relatively simple sentences with a person-action-thing type structure, but inside that structure is all sorts of emergent knowledge about how we describe action, including rules for tense, timing and modality.
It all builds from there, until you reach a point where you are a fluent speaker around the age of 6-7.