College Student & Full Time"RV" Living

Please, don't discount the help available to you on this Forum. Part of the reason that you are being told not to do what you've envisioned is because others may have tried or have at least thought methodically through or own an RV and know the amount of cost and labor involved. What you're about to undertake is not trivial and to do it even semi-successfully is going to be a lot of work. All things considered, buying a used RV with everything in place is going to be cheaper than installing all the necessary bits. You don't have to make that YOUR choice, it's just a fact that makes it a more practical choice.

Get yourself familiar with AC and DC electrical. Here are a couple of links: 12 Volt side of life
Power my RV
Golden rules of electrical and solar

At a minimum, you'll need some type of AC load center with circuit protection to take the AC into the van. Just stringing out a cord isn't safe, there is the possibility of energizing the chassis with lethal voltage. You will need to connect the battery charger to this AC power.

There is a very simple way of handling this. Purchase a commonly used extension cord LINK

For DC, you will have to get a grip on what’s necessary for your needs and how it will be implemented, what the charging schedule needs to be and how much battery capacity is necessary. The battery to which you linked MAY have 110 AH of capacity. That is, conventionally, 55 usable AH's. I'm guessing that charging your laptop, running a 12V cooler, and the draw of the CPAP is going to put you over that 55 AH's. You'll need to do your own math. Replacing that 55 AH's with a 20 amp charger to 90% of the battery's capacity will take about 4 or 5 hours. Unless Walmart has decided to offer 120V service for overnighters, that means you'll be breaking out the generator every day for that charging run to make it for another night.

I did the math and so far, the only flaw in my plan is the total amount of power being provided by the batteries and what is needed to charge them.
Power requirements:
CPAP machine = 2.2A (17.6A total draw during a normal 8 hour night)
Coleman 40-qt. Road Trip Cooler = 4A (96A total draw in 24 hours max)
Laptop = 9.5A (max) (47.5A over 5 hours max use inside van)
21.5" Heavy Duty Swivel Utility LED Light Bar with Rocker Switch x2 = 1700mA (8.5A max over 5 hours)

Not accounting for the fact that Laptop will be charged in school most of the time and not drawing full power every time it's used, lights will only be on at night most of the time, and when CPAP machine is running, laptop and lights will not be running because I will be asleep.
Grand total = 17.3A (max per hour) (169.6A max use in 24 hours)

Based on the math, I would need 2 190A AGM batteries to supply the total amount of power I would need at max drain. 3 190A batteries would provide:

190A per battery x 3 batteries = 570A
570A / 2 (50% discharge) = 285A
285A - 169.6A (max drain per 24 hours) = 115.4A reserve

Again, this is a max usage which likely won't happen. I will be charging my laptop in class most days. I also don't actually plan to spend every minute not in class, in the van. These figures only assume 8 hours of sleep with only the cooler/fridge and CPAP machine running. Waking up and getting ready for class at 6am, being in class from 8-4 daily. And being in the van from 5pm-10pm. And after some research, I found a place to park for the night where I can get power, food, fuel and whatever else I need for the week within 6 miles of my college of choice. Pilot/Flying Js

I know there are other ways to provide power to the batteries such as solar and the van's alternator. I'm not going to focus on solar for now, that's something to deal with later. The van's alternator is an option yet to be decided upon and the wiring issue is something I need to plan out. But I also know that I can spend a little bit of effort to find friendly locations to hook up to "shore power" to provide for charging without using the generator.

You can, like a few others that have posted here, try to get all of bits to come together. All of them I've seen on here do not post about their successful finished RV. I'm guessing that they lose heart and budget in midstream. To accomplish this, you're going to be dedicating many man hours, will have to seek help, and will spend a lot of money. FWIW, I started with some of the basics in place and spent 6 months of almost full time labor and $5K to get it done. I have 40 years of construction experience and had most of the tools available. I also had some of the materials that I needed. If you don't have the above, you can add at least $2K to the budget.

I'm not looking to do a whole lot of work on the van to make it livable. By the time I am able to purchase a van, it will be April so I won't need to do a whole lot of work. I have no intention of doing a full conversion. Only installing some insulation to help keep the inside cool during the summer and warm during the winter. I will not be installing any furniture except for the bed/futon I will use to sleep/sit on. No cabinets will be installed, only shelves and some storage containers. The insulation and walls will be the only permanent installations in the van.