Welcome aboard!
That's a pretty machine. I have no direct experience with it, but I'd suggest what you'd usually do with an RT machine:
1: Check if all parts are there and nothing is missing.
2: Inspect for physical/mechanical damage, warping of rollers etc. Also look for dirt, crud etc. Clean it off if needed. If it has automatic replenishment, thoroughkly
3: Fill the machine with water and power it up. Ensure it's on a properly fused outlet so the fuse blows if something's horribly wrong, instead of the machine + the house burning down. Keep a close eye on it for the first few minutes and verify that the motors run, the racks roll smoothly etc.
4: Drain the machine, fill back up and let run for a minute. Repeat this process a couple of times. This helps to clean tubes, pumps etc. Then fill it one more time and see if the water comes up to temperature. Verify it doesn't overshoot and keep warming beyond the target temperature.
5: With water in the machine, pass a piece of (scrap) paper through it. Verify it comes through to ensure that the transport works as intended.
6: If everything is OK up to this point, fill with chemistry, let it come to temperature and pass a strip of scrap paper through it in daylight. Wash the paper and dry it (e.g. hairdryer). It should be totally solid black. If so, start running test strips & prints through it and enjoy the pleasure of using an RT processor!
Keep an eye on replenishment; if the machine does not have automatic replenishment, I'd suggest replenishing every 20-30 8x10" prints or so. Use the replenishment rates suggested by the chemistry manufacturer.
Please do not be tempted to turn on the machine without any water in it. If you absolutely must, run it only for 3 seconds or so, then allow ample time to cool down. The heating elements heat up *really* quickly without water and may damage gaskets, the housing etc.