Today, I'm going to write about my (new) job (that) i got 2 days ago.

I make a cell phone ingredient. like a case,battery board ( Use plural since you are making more than one)
(Also ingredient is used mostly for cooking, not for electronics)

I make cell phone parts such as cases, batteries and (motherboards).

Before i got this job, many friends (friends) of mine scared me about (the) factory.

there are (I have) some friends who have already worked there.
( there are ----- Whose Friends?---- I have = my friends)

and They said "it is like a continue of army. “
even though i have finished that, i don't know how could i do that. just got another job. if you get that job, you are going to quit just in three days."

My friends said, “Working there is like being in the Army. Even though I have finished, (being in the Army or working at the factory?), I don't know if I I could do that myself. I bet if you get that job you will quit in just 3 days.

haha. There is one day left. and they ( They also) said they will buy me dinner if i do this job more than 2 month(s).
So i should do this job more than 2 month(s).
but i don't this job for a this reason particulary ( don't “what” this job?, no verb)

I announced (to) my parents (that) I'm going to live without (their) financial help from now on.
So i have to keep working here. and After 2 month(s), I will (have) get(saved) a enough money to travel my entire country.
And. After that there will be leftover money, but ( I don't know what I will do with it). and I'm thinking now what i have to do~

A tip
“and” is only used to connect two sentences. You cannot use and at the start of a sentence if you choose to use a period.
EX I will play video games tomorrow. And I will eat pizza (wrong)
I will play video games tomorrow and eat pizza. ( correct)

It's good you are going to live without your parents financial help, that is something we should all strive to do.