Marily Jarolim

My eldest son did. 

Who petitioned for your GC? 
 
If it is indeed IR-5, then the answer to your question is 5 years. So, 06/28/2023
 

Your post is really confusing. So let's figure this out.
 
Do you have a GC? Yes or No? Did you get your GC through your spouse? Yes or No? What is the "resident since" date written on it? Is it a 10 year GC or 2 year? Does it say IR-1 or CR-1?  
I know my first 2 questions are odd. But there is a reason why I asked them. Some people confuse terms.

Hello, all! I migrated here in the US June 2018 and just recently I got married to a US citizen. When can I file my US citizenship. I’ve only been married for 6months but this coming June it will be my 4th year here.

You are not required to but if you plan to travel abroad, you may want to get the GC and the passport under your new name. If not going anywhere, you can just file for citizenship with new name at that time.

Hi,
 
We were on the same boat  To answer your questions:
 
1. You have the options to report or change your name on your GC by filing I-90 form. And you have the option as well not to report or change. In my case, I didn't report/ change it, I've waited to file my citizenship and no problem at all.
    (you can use your husband's name if you want too as well)
2. Since you're a permanent resident you have to wait 5 yrs in order for you to file citizenship and you must be living in the US for 5 yrs physically. You can file citizenship 3mons before you reach your 5 yrs.
    (3yrs filing USC is only for US petitioner and married.)
 
Hope it helps  

Your name cannot legally be changed until your immigrant name is changed.
You may file after 5 years.

No.
 
The 3 year rule only applies to those who have been married to a USC and living together in the US for 3 years.  
 
You have been in the US for 3 years but have not been married for 3 years.

*** Moved from AOS from K1 to US Citizenship General Discussion -- OP is already a PR, intending to apply for citizenship ***
 

You don't need a judge just to use your husbands last name. If the judge/court approves your first and last name change, they will provide the paperwork that you can use as evidence of name change for other documents like GC, SSN.

Yes with any name change you need to update all your documents to reflect the new name. 

There is no requirement to update your GC if you don't want to.  The court order signed by the judge will be your proof of legal name change.  SSA will accept that when you apply to update the name on your SSN card.
 

I don't know about your first question, but you can file for citizenship after 5 yrs as a PR or after 3 yrs as a PR married to a US citizen - and you can actually file 90 days early for the latter. I don't know if PRs applying for citizenship can file 90 days prior to their 5 yr anniversary, but either way the 5 yr rule is the fastest for you.