How can I determine whether a judgement has expired?

Determine if the judgment was renewed within ten years from entry. If in San Diego you can search here: https://roa.sdcourt.ca.gov/roa/

What is the statute of limitations for medical malpractice in Nevada? In layman's terms, please.

1 year from the time of the malpractice or the time you should have suspected malpractice, but no later than three years from the time of malpractice.

How do I find a lawyer to help me when I am falsely accused of something medical / mental injury when I am not a medical doctor.

You need to hire an attorney or, if you have professional liability insurance, notify them for assistance.

Attorney sent a contingency retainer without asking me if I wanted to retain counsel. Can I disregard?

Yes you can disregard. You are not required to obtain an attorney, though you may want to hire your own.

Motion to compel production under subpoena to third party

If they are "personal records" under CCP 1985.3, it is not sufficient time. You can request an expedite by ex parte motion, on good cause. Unless...

You can do each one in a separate cause of action.

How can I get a response from a Walmart in San Diego where I slipped and fell in their dressing room, fracturing my left wrist?

To enforce your right, file a lawsuit.

My question is when a policy clearly states that it can not be accelerated, encumbered,anticipated or sold yet it is ???

Contact professional responsibility/ethics attorneys. This may also have been Elder Abuse.

I was involved in a slip and fall accident at work and was refused medical attention and never reported.

Talk to other attorneys, it may be a difficult case to prove.

Does each wrongful act that constitute the cause of action of a lawsuit has its own statute of limitations?

The simple answer is yes, each has own time limit. But, if it is part of a continuing wrong, the older acts may not be time barred. But other rules...