Do Plaintiffs & Defendants sit on any particular side of the courtroom?

As you are pro se, a status you might wish to reconsider if you possibly can do so, you could choose to observe in that courtroom ahead of time, or ask the judge's staff, or ask a local attorney as to your local practices. It can simply vary district to district. I have also seen it vary from judge to judge in the same courthouse, and vary with a judge depending on the type of docket.

Typically Defendant is on the Left and Plaintiff is on the Right. But if it gets mixed up most judges are ok with the mix up, some judges switch it. But 90% is Defendant Plaintiff.

I agree. The party with the burden of proof usually sits closest to the jury box. If no jury, usually the plaintiff is to the right.