A question for those that have 4 wheeling experience. I am a beginner and have gone out only a couple times. What should I get first? Rock sliders or skid plates. I have the front skid but am looking at adding the transmission and transfer case skid.

I have had 6 different vehicles for offroading and have never had an aftermarket transmission or t-case skid. I have always started every vehicle with suspension, then sliders. If you don't plan on doing any heavy wheeling, I would forego the other skids.

Exactly what he said above.

I've only done suspension and sliders and bumpers (eventually) on my rigs. If you choose your lines carefully you won't need any skids at all.

I only have opinions to give, not really any advice sorry...

If you're doing rocky enough terrain that you feel transmission and transfer case skids are necessary, I'd think sliders would probably be needed as well.

I only have a RCI front skid, but after I put it on I installed sliders for both protection and easier access to my roof basket. Haven't needed the sliders for protection yet, but I'm much less worried about getting close to larger rocks now.

Is your front skid the stock Toyota part or aftermarket? The stock one is only slightly more durable than aluminum foil and won't do much if you're routinely scraping it over rocks; it's more of a gravel deflector than skid plate, really.
*Edit: Just read your sig and other posts, I agree with them; front skid good, sliders good, other skids not really needed.