The words
"to," "too," and "two" are
homophones: they sound alike but have different meanings. The preposition "to" refers to a place, direction, or position. The particle "to" is used before the verb in a to-infinitive. The adverb "too" means also, very, extremely, or additionally.
"Two" refers to the number 2. It's probably the easiest one to remember, maybe because it doesn't look like it should rhyme with "to" and "too." It can be confusing for English language learners, and even native English speakers, to distinguish and use these terms.
I used to make this mistake too. But when Mamma was proof reading my writings, after about the hundredth time she marked it in red ink, I got to where I could remember it.