Sounds like you're already on the right track, having familiarized yourself with the manual already.
Some good info is here in the stickies in the Clone Info/FAQ thread:
Since it's used and you never know how it was treated I would do a full breakdown and clean / lube it. Go through the regulator as well since you never know how long it's been since anyone serviced it. If the reg seat is getting a bit worn, flip it. If both sides are worn, replace it. A spare reg seat and o-rings are good to have in your bag.
Maintaining the Clone is not difficult at all. You seem familiar with marker maintenance so I don't see you having any problems. Most people that complain about maintenance on the Clones have never actually owned one. The drivetrain has more o-rings than most, but the majority of them are static. The trade-off is how fantastic they shoot. After performing maintenance a few times it will become second nature.
While the Clone can handle anything from SLP to HP, I wouldn't recommend using HP unless you don't have another choice. You ideally want to run mid, low, or super low pressure. All work well.
The new Militia Lube they came out with recently is fantastic and I would recommend using this for your newly acquired marker:
If you have any questions along the way just post em up, we're here to help! Enjoy your new Clone