Congrats on having a job you like and a solid intent to reach Financial Independence!
A lot of folks use investing in the stock market to reach that goal. A reasonably safe method is to live off 4% of your stock market investments. If you're wanting an income of $20,000, you'll need 25 times that, or $500,000.
This is a great introduction to the whole concept of investing in the stock market:
http://jlcollinsnh.com/stock-series/$30,000 for 7 years isn't likely to get you to FI in that time frame. It will definitely get you there over time, but it will take longer. Here's a calculator to help you figure out different scenarios:
https://www.investor.gov/additional-resources/free-financial-planning-tools/compound-interest-calculator. Relevant numbers are 7% for after-inflation growth and to compound annually. So, if the market toodled along at the historical average growth of 7% after subtracting out inflation, you could expect about $260,000 in your market account. It would take about 12 years at your current savings rate. Of course, the market might do better or worse than average in any 12 year time span, so you might get there quicker or slower. But you will get there.
Another option is real estate investing to purchase and fix up properties to rent out. Every real estate market is different.
In my own market, I buy homes in the $33,000 to $40,000 price range. Total cost to get them rented out runs between $45,000 to $50,000. At that point, they are worth about $80,000, so we're looking at a $30,000 to $35,000 jump in net worth just by fixing them up. I rent them out for about $800 a month, of which $400 is profit. So, I can count on about $4,800 a year in profit. The rest of the money goes to taxes, insurance, the property management company and repairs. A portion of the rent is set aside to pay for things that haven't broken or worn out yet, but which surely will. Ditto for paying expenses like utilities when the property is empty. I don't have a big kitty saved for big repairs in the first few years, so I have to be able to pay cash or arrange financing if, for example, the HVAC dies earlier than expected.
Here's a 7 year plan for my market given your savings rate. Assumptions are that you start collecting rent the year after you buy the house and that you do a fair bit of the work yourself to keep $ costs down. And that you plough the profits back into funding more houses. The remaining assumption is that you don't have a major $10,000 repair bill before you have saved up enough from gross rents to pay for it.
Year Savings Buy Running Total Gross Rent Profit
1 30000 0 30000
2 30000 -50000 10000
3 30000 0 40000 9600 4800
4 34800 -50000 24800 9600 4800
5 34800 0 59600 19200 9600
6 39600 -50000 49200 19200 9600
7 39600 -50000 38800 28800 14400
8 38800 38400 19200
So, not quite $20,000 in 7 years, but pretty close.
There are other ways to do real estate deals, but this is a simple one that can work. We've been having good results from it.
The Real Estate topic on this forum contains links to good books on how to find and structure good deals.
Hope that is helpful.