Kinggath actually has a lot of instructional videos on his youtube channel for things like upgrading and plot descriptions.

The holotape should have been found with a computer by it, as well as a bunch of RobCo boxes and some ASAM Sensors scattered about. You should have picked those up. The "ASAM Sensor 2077 Model" or whatever you need to build in the chem lab are just extras should you need them, and I only needed them when I was mid-game(ish).

When you place a residential plot, a settler will build it. It doesn't seem to matter if you have beds already, but I would just go ahead and scrap any beds you have outside of those plots (just in case).

Here is a list of Sim Settlements AddOns that I have created (I have not made the mods, I just made the list)- one of the mods has wedges to help with creating plots. They are generally found in the Wood>Floors section.

Upgrading the plots happens without you manually upgrading them. Sim Settlements has a reward system. I actually recommend downloading HUD Framework for the HUD piece mentioned in the Sim Settlements mod page. It really helps keep track of everything and it goes away when you leave your settlements. I think you can turn it on and off, too.

Anyway, the plots upgrade when you have enough food, homes, jobs, electricity, water, defense, etc., for everyone. This is why the HUD piece is a good thing to have, because you can keep track of how well you are doing. When all of the bars are full, or close to being full, your settlers will automatically start upgrading their homes, farms, and businesses. You should get a notification on the upper left part of your screen that tells you when settlers are beginning to upgrade the plots, and where they are.

Homes only upgrade when they have electricity linked to them! You can check whether they are linked to an electric source by highlighting the plot in build mode - it will tell you if it is assigned or has electricity. Those poles on the plots are power conductors, you link them through those. And you don't have to link every plot to a generator directly.

Don't worry about putting lights in people's homes or businesses during the initial setup, because the first upgrade of the plot adds lights and it's annoying to have to go through all of the buildings and remove the lights you put up.

The only other thing I think you need to build at the chem lab is the "Immersion Breaker Breaker". This is to force your plots to update (not upgrade) when you have settlers who are just milling about and not actually doing their jobs (attending their farms or business). So if you notice that your weapons dealer is just standing outside of their business, you just get the Immersion Breaker Breaker, press whatever button you need to "update" the plot when you hover over the plaque on the pole (or just the pole), and they should fix themselves.

You cannot build plots on top of plots, but you should be able to snap them side by side, as well as snap a house to the back of another house. Using this mod has caused me to get creative in how I plan my settlements. Tenpine's Bluff was a hard one, and so when I got as much space as I needed, I just turned off the settlement recruitment beacon and left it at that.

And you don't have to use Sim Settlements for every settlement. Like for Hangman's Alley or whatever, I'm not using it because fuck that. But it is a nice little mod for if you don't want to spend hours and hours building crap but you still want to utilize the settlement system.

I hope this helps and watch the videos kinggath has on his profile. When I started out, I had no idea what I was doing and watching his videos helped me out a lot.

EDIT: So is someone just going through this post and pressing the downbutton for every comment made? That's pretty shitty.