Why the USCIS can not provide any information in my case status as of now?

All you need to do at this point is schedule an INFOPASS appointment to check the status of your case.

Can I get a green card (EB3) for a foreign trained nurse with a foreign Diploma in General Nursing(3 year programme)?

Will be difficult, if not impossible, with a 3 year program degree.

I had a parking ticket.can it affects my record and my citizenship status. Thankd

As long as you timely pay that parking citation, will have no effect whatsoever.

What is considered "proof of enough funds to travel" when applying for a student visa?

Did you pose this question to your school officials?

I had a parking ticket.can it affects my record and my citizenship status. Thankd

As long as you timely pay that parking citation, will have no effect whatsoever.

How can i know my status because they wont allow me to get in the USA without any reason?

Most likely because the consulate received "derogatory information" on you and might have "reason to believe" that... Looks like your visa might...

I am in H1B and i am getting max out in 2 months. my question is below, can you please help.

1) Yes. Employer will then be able to seek the extension of your H-1B for up to 3 years. 2) Yes again.

The countdown of the 90 days is from the date of last arrival.

In our office we let even 5 year olds sign their own applications.

You are confused. There is no oath ceremony scheduling in N-600 cases.