What can I do to protect my child?

File your petition to modify and enforce the parenting plan and just set the matter for a court hearing

What should I do?

file a motion to use Family Wizard it is an e-portal website where parties can exchange information, documents, etc.

How can I keep my house if I have not income but alimony

Don't sit around waiting for alimony, get a job and also apply to the court for alimony too.

Will the court be likely to grant this?

Family Wizard works so this request should be granted

Do I have some sort of restraining order against me?

contact the clerks office all the records are there. Find out if you are named in an injunction

You don't get a redo. Yes you can re-open the case but you cannot re-hash matters that were already litigated.

We have an order for mediation to set specific dates. But other parent is abusive and ignoring my request for mediation times.

set the date without him then contact the court and the mediation dept. to issue the notice.

Is it worth suing?

You should consult an injury attorney, you can make a claim against the landlord's insurance co.,

How can you be legally served papers if you're not even present?

Agree with other answers, you have in fact been legally served.

Where would my son go to school at?

If not married to him then you get to decide the school unless the court decides otherwise.