Camping and Hiking can certainly be expensive hobbies. Serious enthusiasts can spend thousands on gear, and this is often something that a less experienced person might see as gatekeeping them from enjoying a great time in the outdoors. While proper gear can certainly make things more comfortable or easier, this shouldn't stop you from trying it yourself. Remember, humans survived in the wild for centuries before you could stop into your local sporting goods store and grab a tent and sleeping bag. While you should carry some basic tools, you don't need tents or even sleeping bags to immerse yourself in nature.
If you own a car, you may have everything you need for a great trip already. Road trips are always a great time, and utilizing your vehicle as your shelter will allow you to travel to a variety of places at a relatively low cost. Of course you'll need to fill up the tank as you go, but if you don't mind sleeping in your car, you can save big on accommodations. There's many parks or large parking lots that you can park at for free - but always be sure to check local laws before setting yourself up for the night. You don't need a tricked out van to do this either, any standard sedan, coupe, or SUV can do this. A larger vehicle will help give you more storage, and might be more off-road capable, but it's not a necessity to get out there.
Depending on if you'll be going yourself or with others, you'll need to plan accordingly for how much you can pack. If you have a hatchback or open trunk, that's probably going to be your sleeping area as well, so you'll need to have enough room to move your gear aside to set up a sleeping area. While you can simply sleep curled up in a seat, this is not the most comfortable. If you plan on multiple hikes during this trip, you'll notice your muscles stiffening up from sleeping a huddled position constantly.
The main things you should be concerned with packing in your vehicle are some basic hygiene items, some blankets and padding for sleeping, if you don't own a sleeping bag, and plenty of hydration. Basic survival tools are recommended, as well as a roadside assistance kit, should anything go wrong. You can pack additional items to help add to your experience, such as cooking equipment or pop-up fire places, hiking/climbing gear, and so much more. The beauty of using your vehicle as your shelter is that it's completely mobile, allowing you to plan the materials that best suit your destination.
The freedom to move is what makes car camping unique, as you're not tied down to experiencing just one environment. Especially in the United States, you could be the arid deserts of Death Valley, and the next day be surrounded by Sequoia trees in the Redwood Forest. The only limit you'll have is how far your tank can take you, and of course, how much time you have.
As always, be sure to plan accordingly and bring additional food and water. If you plan on spending time off the beaten paths, be sure to have additional survival tools and roadside assistance tools to reduce the risk of becoming stranded with your vehicle.