Welcome to the forums.
You will find the commands reference/search tools two ways;
When you downloaded PAC Project, the manuals were installed on your hard drive.
Check them out where you installed it, by default they are under C:\Program Files (x86)\Opto22\PAC Project 9.2\Manuals
The command reference (which, since its a PDF, is searchable) is doc 1701. But dont forget doc 1703, it lists the commands with a one line description.... Pretty handy once you get past the basic commands.
When you are in PAC Control, just click on the menu 'Help -> Manuals -> Command Reference'. (You can also search from there as well since its the same doc).
PAC Control in debug mode will poll data from the I/O as fast as your network will allow it.
For an application like your nursery, that's going to be way too fast.... You really don't need to poll your temperature and water status every 50ms or so, that's just a waste of your network and its pretty 'dull' to have to try and look at tumbling numbers in PAC Control and keep track of what its trend over time is/was.
Far better to get your strategy up and running and then make a PAC Display project to match.
You can have PAC Display poll your data at a much more sane rate of something like once every 1-5 seconds.
You can also make graphs, which is going to help you and your staff follow whats happening in each zone of the nursery much easier.
Here is an example of a PAC Display window of a building with Opto 22 controls in it, note how the AC is broken down into zones;
Think of it as one green house and its broken down into zones, showing perhaps temperature or water.... Really, its just an example to give you a feel of what can be done.
You can click on each zone and get more data from there, and also open a trend, here is an example of that graph screen;
Note this is also a good example of a bad example.... I have chosen a really bad time scale for this trend. Make sure you pick a time scale that clearly shows the data points. (The manual makes this clear... Yeah, I should have RTFM'ed (Read The Fantastic Manual).
I guess my concluding point is that what you are looking to use Opto for in the nursery is exactly what the product is designed for.
The nice thing about it is that you can get started with a basic control system and graphics and expand it as your knowledge grows and as you see the power of putting an automation system into action at your nursery.
If you are still needing a bit a of a leg up, consider downloading the PAC Project Demo, it will get you started with no hardware and give you a feel for what and how Opto can do the do.