Help translate

[maybnxtseasn]

"cuando tu llegas a trabajo venir a mi. yo nesicito a decir algo"
i'm wanting to say
"when you arrive at work come to me. I need to tell you something"

i get confused on when i need to conjugate certain verbs.

what did i do wrong on this i know it's wrong

[Elaina]

"cuando tu llegas a trabajo venir a mi. yo nesicito a decir algo"
i'm wanting to say
"when you arrive at work come to me. I need to tell you something"

i get confused on when i need to conjugate certain verbs.

what did i do wrong on this i know it's wrong

My idea as to what it should say......
"Cuando lleges al trabajo, ven a verme. Tengo que decirte algo."
"Cuando lleges al trabajo ven a verme porque tengo algo que decirte".

They both say the same thing.

As far as what grammatical rule(s) was broken, let's wait for the brains of the forums.

;)

[Rusty]

You have many things correct.
Cuando llegas al trabajo
Note that I left out the subject pronoun tú. It isn't necessary. The conjugated verb ending tells us which person you're referring to. The definite article el is needed before the object. Since llegar is always followed by the preposition a, the combination of a + el is al. This part of the sentence is a complete thought. What follows 'work' is another phrase.
ven a mi
This phrase begins with a command in English, so you should have a verb conjugated in the imperative mood in your translation. The command (imperative) form, when you're talking to another person, has two possible conjugations. If you normally treat the person in a familiar way (as you did in the first part of your sentence), you would use the 2nd-person imperative form. If you would normally use usted with that person, you would use the 3rd-person command form. So, checking the verb charts for venir, we can see that the 2nd-person conjugation in the imperative mood is ven. You got the prepositional phrase wording figured out, but you'll need to accent the word mí.
So, "come to me," is "ven a mí."
(The more common wording would be "come (to) see me." The command form doesn't change. "To see" is ver. When a verb isn't conjugated, like the infinitive 'to see', any object pronouns that verb may have are simply suffixed to it. The verb ver takes a direct object, so you would use the 1st-person direct object pronoun me.
So, "come see me," is "ven a verme."
I need to tell you something
Again, you don't need to use the subject pronoun (yo, in this case) because the conjugated verb ending tells us who the person is. Necesito is the correct spelling.
The verb necesitar takes a direct object. It isn't followed by a preposition (as required for the verb llegar). The direct object can be an infinitive. You correctly chose decir. You didn't translate the word 'you'. That is an indirect object pronoun that can be suffixed to the unconjugated verb, like so: decirte
You got the rest of the sentence correct (except I like proper punctuation and capital letters at the beginning of my sentences).
So, "I need to tell you something," is "Necesito decirte algo."

Elaina opted to use the subjunctive in the first sentence (llegues instead of llegas). The use of the subjunctive mood casts some doubt as to whether the person will show up for work. I used the indicative, indicating no doubt that the person is coming in. She also used a phrase in the second half that offers alternate wording. You can choose either way to say what you wrote. I kept your original wording because it was easier to explain. :)

[irmamar]

I agree with Elaina (despite the lacking "u" in "llegues" ;)). You could say also: "Al llegar al trabajo...". :)

[CrOtALiTo]

I agree with Elaina.

She's answer are accurate.

Bye.