Difference between To, Too and Two
One confusing set of homonyms involves to, too, and two. A clearer understanding can prevent numerous little editing errors and allow your readers to understand your ideas better.

TO
To offers writers two uses, as follows:
To as a preposition: To is one of the most often used prepositions to introduce a prepositional phrase, which indicates location and condition, among others.
For example: to the store, to another city, to the boats.
Punctuation: No commas are used with this To.
To with an infinitive phrase: an infinitive phrase consists of to + a verb.
For example: to dance, to sing, to have a great time.
Punctuation: No commas are used with this To.
TOO
Too offers writers two uses, as follows:
Too means “in addition to” and is used at the end of a sentence for emphasis.
For example, He went to Europe, too. I liked that one, too.
Punctuation: Always put a comma after the word before too.
Too is used to refer to excess or degree of something. It functions as an adverb and is placed within the sentence.
For example, She was too noisy. Harry carried too much in his backpack.
Punctuation: No commas are used with this too.
TWO
Two is the number 2 (between one and three).
For example, Two birds splashed in the birdbath.
Punctuation: No punctuation is used specifically for two unless the phrase or clause requires a comma according to its function.
Tip: Most style manuals say that you should spell out the word two (rather than using the numeral or digit 2) for any numbers between zero and nine or ten (the upper limit varies by style manual). However, if you have a single-digit number in the same sentence as one or more multiple-digit numbers, use numerals or digits for all numbers. For example, “When 42 writers attended our workshop, 13 entered the contest but 2 left early.” Be consistent in spelling out numbers.
By using these words correctly, you can save yourself a lot of headaches from making little errors and confusing your readers.