Hey Kincaid, that's awesome that you're interested in real estate at a young age. You already have a huge leg up on most of your peers. Now, I don't know what your overall goals are or what you're planning on doing after high school.... whether you're going to college, pursuing another career, or would like to get into real estate full time... so I'm going to give you the overly in-depth answer that I wish I could have told my 18 year old self.
I grew up in the country, working with my hands, around family members that could build a house from scratch. I also got my real estate license at age 23 and learned massive amounts of priceless information about the industry through experience and by sitting through every Keller Williams training class possible. These are the books that I still wish I would have/could have read when I was 18:
Mindset/Money Management:
Rich Dad, Poor Dad by Robert Kiyosaki- the foundational real estate book everyone should read
Total Money Makeover by Dave Ramsey - the foundational personal finance book about budgeting and saving your money because you'll need to save as much of your money as possible to succeed
The One Thing by Gary Keller - foundational book on how to stay focused on what really matters
Real estate books:
How to Invest in Real Estate by Brandon Turner - Real life stories on many different ways to invest in real estate
Real Estate Investing with No and Low Money Down by Brandon Turner - Breaking the myth that you need massive amounts of capital to become wealthy in real estate
The Book on Rental Property Investing by Brandon Turner - explains how to buy and hold property and why it's the foundation on obtaining long term wealth
Long Distance Real Estate Investing by David Greene - this explains the systems anyone can/should use to buy real estate in any market around the country including your own local market
Buy, Rehab, Rent, Refinance, Repeat by David Greene - explains how to fast-track your wealth in real estate by recycling the same money to buy property after property
Flipping Houses by J Scott - learn the flipping process to increase your income and have more money to buy rentals
Recession-Proof Real Estate Investing by J Scott - learn how our economy works, how it affects the real estate market and how to prevent yourself from losing your properties
Managing Rental Properties by Brandon Turner - in-depth, how-to guide on managing properties and how to organize yourself; even if you use a property management company, it'd be great to know these skills
Finding and Funding Great Deals by Anson Young - ideally, your main method for finding deals should be by establishing great relationships with Realtors, wholesalers, and other investors but understanding how to find off-market deals and later pursuing these deals after you've established yourself could be beneficial
Rehabbing/renovation:
Book on Estimating Rehab Costs by J Scott - learn how to define and calculate your renovation budget
How Your House Works by Charlie Wing - visual guide to understanding and maintaining your house
Complete Guide to Home Inspection by Roger Robinson - know how to inspect a property and what to look for when looking at a property
Renovation by Michael Litchfield - In-depth look at how to do almost any renovation project
Complete Guide to Contracting Your Home by Kent Lester - fully understand the contractor's job and how to effectively communicate with them
Dream Home by The Property Brothers - understand the mindset of a home buyer and which renovations are most sought after
People/Negotiation... real estate is a people business and your ability to effectively communicate with others and build relationships will end up being the most important part of your real estate journey:
How to Win Friends and Influence People - foundational book on building people skills and possibly one of the most influential business books of all time
The Book on Negotiating Real Estate by J Scott
Never Split the Difference by Chris Voss
Pitch Anything by Oren Klaff
Okay, now I'm looking back at this list and realizing just how exhaustive and probably overkill it is for an 18 year old. Or is it? As an 18 year old, you're going to have to work even harder for people to take you seriously.
If your goal is to pursue a non-real estate related career and just buy a few properties for some extra income/investments then you'd probably be fine by reading a couple BiggerPockets books and listening to the podcast. In fact, to start... I'd just work on building my credit, getting a good W2 job, and reading House Hacking by Craig Curelop.
However, if it were me, and I was 18 with the goal of becoming a real estate millionaire and financially free by the age of 25.... then I'd get 2 jobs (preferably jobs that interact with the public and increase people skills), reduce all of my spending, save as much as I could, read all of these books twice, listen to all the BiggerPockets podcasts, watch all of the free webinars, read blog posts, watch youtube videos, go to local meet ups , network and immerse myself into the world of real estate. Then after a year or more of this... seek out and befriend an experienced real estate investor, bring them as much value as I could, get into their world, learn as much from them as possible, partner on some deals, hustle, probably fail, pick myself up, probably fail again, pick myself back up again, continue learning, continue hustling, continue to slowly succeed until I master the process and live an absolutely epic life.