Head-2-Head Classic / How to LL?

I'm writing down some random thoughts and tips, and I think though a few rounds of restructing this will become a nice little guide on LL for beginners. Please contribute!
 
Installing

'LL' means RCT1 plus the second expansion (which automatically includes the first expansion, AA/CF). The game has been published in several ways; originally through separate discs, later assembled into a single 'RCT Deluxe' physical disc, as well as a few digital releases. The physical releases also come in different versions varying per region. This only really affects some trainer issues.
 
For opening most parks made by the community, which often includes some hacks, the game requires a patch or two. Posix's classic RCT1 guide covers these. What I do when I reinstall: install the game and the expansion, and try opening a park like Busch Gardens San Simeon. If it doesn't work, install the official RCT patch. Try opening the park again. If it doesn't work, install the drexler patch.
 

Basic tips

RCT1 has a windowed mode, which is great. However, when alt-tabbing, or clicking outside the window, your computer will not respond. You will need to right click outside the RCT window first, before you can do stuff outside RCT1 again. It's a habit you'll quickly develop. Just be careful with the right click, you may accidentally remove scenery on the edge of the window if you're not careful. In heavily hacked parks, this may even trigger an error trapper, which brings me to another important tip:
 
Save regularly! RCT1 doesn't have autosave like we're all used to by now, and if you're diving into hacking, errors can occur in unexpected places.

Trainers

One of the nice things about LL is that you can make stuff with just the game's basic functions! Something like Toreador was made without any trainers. Some trainers can open extra doors, however.

I recommend using Codex foremost. It lets you raise/lower scenery, a bit like OpenRCT2's tile inspector. This is worth a separate tutorial, and I won't get into it now. What Codex also has is easily accessible sunny weather, a button to water flowers, and instant zero clearances and restoring zero clearances, in a compact window.

Here's a mini tutorial for some basic Codex functions:

The Beast trainer is a beast of a trainer that lets you mess with rides a bit more. I recommend just downloading the trainer and seeing what you can do. Its zero clearances functions are a bit more advanced than Codex. When Codex doesn't work, try the Beast Trainer. Sometimes, upon opening the trainer, it will ask you to select which country version of the game you have. If you don't know, trial and error.

4 Cars per Trainer is the precursor to RCT2's 8cars, and has a lot of similarities. In RCT2 it was the quintessential trainer, but it's different in LL. You don't need it per se. It only works with the US version of the game, too.

Lastly there's the Savegame Modifier. It's an external tool, not something you run alongside the game. It's most important function is adjusting the entrance and peep entry point. Takes some practice, but most people should be able to figure it out in a few minutes without much trouble.

Save regularly! RCT1 doesn't have autosave like we're all used to by now, and if you're diving into hacking, errors can occur in unexpected places.

I concur! Created several black holes without noticing and they're apparently not always easy to fix...

Forgot an important tip:

DON'T use the mountain tool, except for on an empty map. Or save your game, try it, and see how it fucks everything up.

accidentally using the mountain tool feels like tripping over your own feet

my number one tip is 4cars is better than beast you wont regret it nerds

Another tip!

If you can't get trainers to work ("No process"), mess with the compatibility settings of the trainers. For example, set the compatibility mode of the Beast trainer.exe to Windows XP service pack 2. This tip saved SSSammy's life.