To Mr. Loop:
Here's a bit of what I can tell you. I'm just gonna type as I think so bare with me.
There's a couple types of basic park layouts to follow. One of the easiest is the Islands of Adventure style. Basically, your park is a circle around a giant lake. You can have branches and stuff, but it basically all is one big circle. I mean, you certainly don't have to do a lake, it could be a mountain or something else. The next type is Disney hub style. You have a midway going to the center of the park and the spokes like a wheel branching out to different sections around a central feature, like the Disney castle. All these can be interconnected from the outside, but it's main formation comes from that center area. The next type is just a double or triple loop format. I find this one harder actually, but it just involves a couple interconnecting loops. I think Kennywood may be one of these. Like, it has a midway and then two circles on either side. The last way is something like Blackpool where it's just an unorganized mass of stuff. This one is really only good if you're going for that carnival atmosphere. But in short, the IoA style around a lake is really your best bet. I mean, you can modify it however, but I'd just go with that kind of thing.
Another important thing to remember about parks is to divide them into themed areas. If it's not all the rides tend to come one right after the other in a straight line thing, which looks horrid. I've found that when starting a park, it's best to pick places for sections and start building. Never just build out from the entrance, it will all end up packed together. When doing sections, be sure to have like a staple coaster and then some flats. Don't overdo it on rides in a section. Maybe 5 flats max per section, depending on how big the park will be. Also, remember this about pathing: straight lines are bad. I can say that I used to connect all my sections with just a 3 across straight line path with some bends and stuff. Not good. Paths should be free-flowing, constantly changing size and looking natural in place around the architecture and rides. Make sure every piece of path you put down (and architecture, I'd say) has a purpose and a good reason for going there. I think the following park links will help.
Anyway, onto the links. These parks are New Element Spotlight Parks, the highest honor a park can get. There are others besides what I post here, but a lot are RCT1. Ask me if you want others, as I have a lot of recommendations. I've also included a link to Rivers of Babylon, my all time #1 RCT2 park. So here you go, thanks for reading.
Rivers of Babylon:
http://www.nedesigns.com/?ne=spotlight&s=rob
Bijou Magique:
http://www.nedesigns.com/?ne=spotlight&s=bijou
Ports of Magia:
http://www.nedesigns.com/?ne=spotlight&s=pom
Islands of Enchantment:
http://www.nedesigns.com/?ne=spotlight&s=ioe
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Alright, I'm done with that... now for your question, Dude.
Invisible track is a real simple hack with 8 cars. All you have to do is go under the edit ride stats menu and find your ride. Then change the track type to some flat ride or food stall, like "Crooked House". Click apply and track will be invisible. However, be careful. Now you've given the invisible track properties of the Crooked House. That means that the height clearance above the track is now like 8 squares. So you'll have to zero clearance stuff over it from now on.