new to model trains and z scale trains

Hello everybody, I bought a up z scale starter set and rokuhan oval railset r062 . I also bought a nce powercap .    As of right now, I have the railset up and running on battery power. I plan on buying more track to be able to build the add layouts to railset r062 and rokuhan layouts  L and Y; the reason being if I get bored with layout I can change it. My layout will be on a door 30 inches by 60 inches. I would like all the turnouts to be dcc controlled. I've been reading about all the different products to control them, such as accessory decoders that can control two turnouts at once.  What I did, was tally up the different track types of the layouts from above and took the highest number of each track type I need. But on rokuhan layout Y, it says some L110, L220 needs to be trimmed, so I'm not sure how much of this track to order.  As for other train items, I'm not sure if I need the two types of rail joiners, and how they work with the turnouts and double slip turnout in layout plan y.  I would like to use rokuhan track plug and play wires, even if I have to splice them to use them, because I have dexterity issues. As for track L 110, L220, L55, I'm not sure how many power feeder, extension wires I need? Also, the same would go for the turnout wires. As for the locomotives, I have a up gp7, 2  em sd 45, for which I would like to get decoders. As for power pack, I have the rokuhan co-2, for which I will be buying an adapter, and it is this enough to power my layout. My goal is to build this layout the most affordable and efficient way. I 'm excited about this layout. Also, as of right now, I only have three freight cars to pull and like the autolatch couplers. How are micro train, full throttle, intermountain freight cars? Again, I'm into the plug and play approach. Lastly, thank you for any advice you can give me to keep the cost down!   Thank you from Kevin, the new train owner!!! p.s.  Sorry for the long post!