Is this introduction OK?

[Immabe]

Sometime in our lives we have to make momentous decisions. We either have made a propitious selection or regret our decisions. The poem, “The Road Not Taken” written by Robert Frost is how a road chosen by a traveler had an impact in his life. Through his poem, Frost have shown that the decisions we make should be chosen carefully because not only will it affect our choices in the future, but there is no going back.

 

[Rose]

Suggestion.
The road........tells how a chosen path had an impact on one traveller's life'.

...Frost has shown....

...not only will they...........but there will be......

 

[Laurence]

Your second sentence should be present tense: "Either we make a propitious selection (better: "choice"), or we live to regret it." In the second sentence, it would be better to say "shows how a road..." in which case you could delete "Through his poem, Frost has (not have!) shown that." And the pronoun referring back to "decisions" has to be plural also: "not only will they..."