When you are finishing/just finished residency, get a biggerpocket account. You really do not need any books, ask questions on biggerpockets/watch youtube videos. Get a zillow account and spend 6 months looking at prices in your area, get a feel for what are good areas, look at price trends, figure out the entry point. Save up 100K, get a place and LEARN. You must LEARN from actually doing.
Mistakes will be made, but with a big MD shovel you can buy one ever other year. In 5 yrs, you will have 3 places that may not cash flow but should have some appreciation/equity. Look into LTR/STR/MTR. Each area has its own niche.
After 5 yrs figure out if you want to continue building your portfolio. If you want to diversify, look into Syndicated RE which is passive with historically high returns but you must pick the top operators; Its an operators game.
In 10 yrs and 6 properties, you can decide to leverage or pay off the homes with the RE income. In 20 yrs, if you choose to pay off the RE, you should/could be mortgage free with 6 properties all paid off. Assuming avg homes are 500K, that is 3M in properties that should create a conservative income of 150K assuming a 5% Cap rate.
Along the way, you will meet alot of great connections. Good Mortgage brokers, building contractors, like minded people. They will open a new world of options that the average man do not have access to.
This was essentially my playbook that took me 10 yrs to fine tune and what I would tell a newly minted doc to do.
I bought my first property 7 years ago. Currently have 9 properties not including my home that all cash flow with mortgages currently at about 30% LTV. In 5-7 yrs, I could use the income to pay off all the mortgages leaving me with NOI of about 300K/yr.
I started syndicated RE 4 yrs ago, currently in 7 properties and cashflows about 80k/yr.
Caveat that this was during low interest and RE boom. You can't predict the future, but I feel confident that there are always good buying opportunities in all economic environments.