Before investing, you should have a 3 month emergency fund which you would leave in cash. That way if something happens, you have money available to deal with the problem. If you have money left over, then how you invest it depends on your time horizon and risk tolerance. For example, maybe you want to save that money for retirement? Assuming an 8% return (the stock market has returned higher than that over the long term) that $4,000 would be worth over $125,000 in 45 years. You could put it into a Roth IRA and then you wouldn't have to pay tax on the earnings. If you don't want to wait that long, invest in your education by reading books (such as Pirates of Financial Freedom) and researching money-making ideas on the internet. There are very few "get rich quick" ideas that actually work, so be sure to do your research before spending any of that money. Your best bet probably is to not spend any of it yet and earn extra income by doing freelance jobs.
You need to learn the difference between incest and invest.
Almost zero chance you can gain $500 on a $1,000 car. If you want money, get a regular part-time job.
FIrst thing I would do is INVEST in a better education and learn English.
save some for a remedial english and proofreading class .
You can always try making videos for Youtube.
make sure they are related and then rub them together vigorously