Let's go over some really basic bits to grammar that I find people often get mixed up in. This is aimed to be a nonchalant aid for those who get confused from time to time. I'm not pointing fingers, or trying to make fun of anyone. This is to teach, not to bully.
There, they're and their.
'There' is referring to a place. "He is over there."
'They're' is 'they are' put together. "They're over here."
'Their' is claiming ownership of something. "The group shook their heads."
Next part. Breath and breathe.
Breath is a singular exhale or inhale or even a single cycle of both. "He took a breath of fresh air."
Breathe is the act of actually breathing. "She needed to take a moment to just breathe."
To add another: We're, where, and were.
We're is a contraction, which is two words put together (we are.) "We're going to go to Disney Land!"
Where is referring to a place, usually in question. "Where are you?" Or "This is where the bears like to fish."
Were is the past tense of are. "We were getting our hair done. But not anymore."
Next. Affect and effect.
Affect is the process of something being done to another. "The father was deeply affected by his son's speech."
Effect is what is being done upon another. "The spray's effect was to ward off bugs."
Another tip. Paragraphs. A paragraph is supposed to contain five to six sentences. And two different people cannot speak in the same paragraph; "Anything like this." Each conversationalist needs their own paragraph.
Some more that have been pointed out in the comment section. I'll go over these too.
I'll point out the difference between to, and too.
'Too' has two different meanings. It can mean 'as well.' "Logan wanted to come along too."
And it can also mean something is undesirably over an amount. "My Aunt gave me way too much soup."
I would go into detail about 'to' but it has a LOT of definitions. Odds are if the word you're looking for isn't 'two' or 'too' then it's likely 'to.'
I'll also point out the difference between than and then.
Than is used when comparing two things. "Father was shorter than Mother."
Or providing a contrast or exception to something. "Other than his sister, the Barber has no living relatives."
Then refers to all those other ones like marking a time, transitioning into the next frame of time, meaning in addition or therefore.
That's all for now~ happy to help~