Not a millionaire but just over half way there if that means anything to you. At the end of the day, millionaires' advice isn't going to work for everyone as it's down to the individual. However, mindset is very important which is something we all can learn.
My advice? First of all, find your drive. You need the drive to be able to achieve goals that aren't immediately in sight, or even on the horizon. To use as an analogy, let's say our goal is to achieve a native level at a foreign language. It's unfathomable during the first week but you know if you keep going at it, you'll get there. But in order to do so, let's break it down. You need:
1. Immersion. You need to talk with natives to get the know-how and how to speak like them. Theory alone only gets you so far with a language. Some people study for years but can barely put together a sentence.
2. Regular practice. Speak the language, learn the grammar, join meetups to practice.
3. Set milestones. Take on the level 1,2,3,4,5 exams.
In the context of accumulating wealth, let's say for immersion, you talk to people in the industry, develop connections, talk to fellow entrepreneurs. For regular practice, you save money and eye further ways of increasing passive income. Whilst doing so, you study up on formulas, terminology, etc. How do I calculate rental yield? What percent of borrowing is considered high leverage? How do I know if this stock is in an overbought or oversold state? For milestones, let's say, for year 1 and 2, I will work hard in my day job and save capital for investment whilst studying the knowledge in my chosen investment area. Year 3/4 I will start with low risk investments to get some toes in the water. Perhaps letting someone manage a stocks portfolio for you, you study which and why. Or buying a cheap buy to let business that doesn't require much DIY to get onto the rental market and start earning a modest margin. Year 5/6. I will have made a modest amount of money and learned the ins and outs of the trade. I will choose my own investments and up the risk to a level I'm comfortable with, relative to my experience and understanding. (Perhaps choosing your own funds to invest in, taking on properties that need more work, etc).
Just by doing this you start to develop yourself and naturally pick up the skills and experience needed to manage your investment portfolio.
For me, it's all about increasing passive income whilst working my day job. I have the job security to pay the bills but with the mindset that I will earn more money and stash it into my savings for reinvestment. I've just turned 25 a few months ago and had my goals since 21. Since then I have a small property portfolio (monthly income + long term capital growth), trade forex in my spare time (short term) and some money in some low risk funds. As the saying goes, you need money to make money. So for most people, the first step will be to save enough capital to invest. You don't need to be a doctor or lawyer but you need to know how to save. A doctor saving 10k a year from living extravagantly is still saving less than someone living modestly and saving 12k. I'm a programmer myself and my younger cousin is a civil engineer. We both started from scratch but in our own ways, developed as entrepreneurs. We didn't start with a doctor's salary but we were saving a decent amount each month with sustained drive (he rents a cheap single bedroom with bills included). He's been constantly reading books on stocks and investing in companies and has already made a decent amount of money putting what he learned into practice (started with around 40k capital, saved from working day job). We share our expertise and knowledge with eachother and I recommend doing the same, to find an investment buddy to take the journey together.
In terms of language learning, I'm currently studying 3 languages, one of which I've been studying since I was 18 and I am quite fluent in. I study everyday. I don't lose motivation. I don't have those days where I "can't be bothered" or need someone to set a schedule for me. No, you have to be the type who can set their own schedules. You are responsible for your own learning. I take this principle with learning how to invest. Not everyone is born purchasing goldmines of a property, winning trades 80% of the time and buying stocks at the right time. No, you have to start from scratch, maybe learn how a loss tastes. It's from there that you adjust as an individual, slowly minimizing losses and maximizing gains. Once you know how to make money, the rest is down to time. You can set a faster pace by being more active in investments but don't let it affect your life. There's more to life than money and you can easily lose what you already have and should be thankful for. This is why passive income is essential to getting to your goal. You have to let the money work for you. Not the other way around.