There are many schools of thought about what matters more vs less in poetry and rap but I am one of those more on the side of skill and wordplay mattering.
You can't be lazy with your flow or metaphors and expect to be considered a proficient poet, unless you are delusional.
I am going to constructively criticise you here, do not expect a fairytale with a happy ending, damsel in distress.
While this can be a title, it's a poorly formed one considering that the 'for' means 'made for' as opposed to 'if it wasn't for my knight' and you take the last 3 words of that. This is not a poetic start, in fact 'Knight' on its own would be the most poetic way to entitle the piece out of these three words but it's not that good for the title. Something better to do would be an indirect reference to his knighthood that you refer to in the poem. This is how to keep things fresh and how so many cliché pop songs end up able to be published with unique titles.
My Knight rides to my tower,
He’s always been a dazzler ❤️ .
Wrong. If you want to do this as a single line you have to at least rhyme 'tower' and 'dazzler' with 2 syllables both to make up for it. That's not to say that doing that would be bad, if you do pull it off that's top tier rapping.
So aim for something like this:
My knight rides to my tower, he's always dazzler,
Now aim to either compliment how soft he is or how tough and gritty he is.
For a sensitive boyfriend:
Not to deflower, but to pay my ransom,
This can then lead into you saying that if they scam him, he's got the heart and/or mind to still push through for you.
For a tough, gritty boyfriend:
Never overpowered, out-done or out-handsomed.
This sets you up to not need to fuel his ego much in the future lines of that stanza and to be more creative with where you take it.
Inside I await,
For his black horse to reach the gate.
Black knights and black horses were known to be the evil ones. Robbers had them. Perhaps you are saying he's an antihero or antivillain even. That is fine but make it clear. The black horse was commonly ridden by those who fought against the 'prince charming' type.
Also, consider how easy this is to milk for extra rhymes. You basically stopped it for no reason.
I await my fate,
I contemplate how great he is upon his horse on which I'll jump and with him, lay my weight,
Just that alone has so much more skill in the rhyming and flow.
note that the 'tem' 'his' and 'him' is a very clever flow technique that few rappers know of. What it is achieving is keeping each intermediate syllable sounding similar enough to the next while being a different word. 'tem' and 'him' actually rhyme because 'tem' in contemplate is said more like 'tim' when delivered fast.
I jump on, we're now running with fright,
From the oppressive tower now outta our sight.
You already had 'tower', why are you using it to rhyme with outta? Why add 'our' after outta? No need.
Let's rethink this also because 'running with fright' emasculates your oh so manly knight... Also why are you frightened when with him? That is something to consider about how you feel with him as it's a Freudian slip that you don't truly feel safe with him.
Think more like this:
On the horse that gallops with a force that's frightening,
I'm Sandy to his Danny and we move slick as if it's grease lightning.
This is an extremely strong play on words but I understand that you probably are in a generation that has no clue what Grease Lightning is, nonetheless you get the idea.
We run into night,
With all of our might.
Might/power is often held as a separate power to speed, also speed is known to have the sprinting variant and marathon variant. Are you complimenting you and him on enduring a lot as you go along or on how fast you him push through challenges? Make sure you are clear on the intent of your metaphors before slapping them in.
Eventually we reach his house,
As quiet as a mouse.
Spending the rest of night together,
More happy than ever 🥰.
You are too young to be writing this in a poem, this is also not the best way to put how you arrive. Is he a ninja? Okay, then make it clear. He may not think being quiet is a good thing.
Making our way the very next day,
Our horse blessing us with a happy neigh 🐴.
Someday we’ll run away together,
Like birds of a feather 🐦.
Birds don't run but this combination of animal metaphor was actually the best attempt at metaphor 'stringing' within the poem. Good job.
I have to return now my knight,
But dont turn white.
White knights are the good guys in folklore, again you are saying that he is bad for you.
This is actually a bit scary because even if he's a 'bad boy' type, it implies (combined with the other Freudian slip) that he is toxic for you.