Can I get some pointers on a plugin that places a brick based off of mouse location?

I'm trying to create a plugin that when you click it places a node and if theres more than 1 node (which will have to be the case) it'll create a semi transparent part connecting those 2 and when you click generate ( I can make the GUI) it'll create a Invisible part between the 2 nodes of that angle naturally 30 Y the X or Z will be the same size as the part connecting the 2 nodes

(Sorry yes yes I know this isn't a request site but I have no Idea how to do this or where to start)

I mainly need help on creating the nodes and the part inbetween I can figure out the barricade between the 2 nodes

but if someone could give me some example script and some links to get started I already have the plugin base set up I just need some help!

local plugin = PluginManager():CreatePlugin()

local toolbar = plugin:CreateToolbar("Blockade Builder")

local button = toolbar:CreateButton(
    "Blockade Builder 1.0", 
    "Click to start creating Plugins", 
    "" 
)


button.Click:connect(function()
Print('Preparing for Node placement')
end)