Before anything else, read up on the basics of economics.
- What is supply and demand?
- What are funds?
- What are and how do stocks work?
After that, there a few things you need to ask yourself before you even think about investing in anything:
- Do you have a (secure) job that, in case your initial investment fails will not impact your current way of living?
- What is your investment horizon? Can you live with the fact that you will not see the money for the next couple of years (maybe even decades)?
- Do you plan to invest periodically the moment you start? After the initial deposit of 500 dollars, will you deposit ever month a certain amount?
If you have an answer to those questions:
- Do you feel comfortable working purely online (and maybe if you are guided by the broker you will start with)?
- Do you really wish to do nothing at all and a pay premium for it (i.e. through your preferred bank)?
- Do you have the time to follow up on your invest periodically (depending on your investment)
- Do you wish your investment to return cash?
Once you answered those questions I could make a simple first suggestion:
- (Not) confident at all and low to no maintenance with uncertain horizon: Go see a (retail) bank.
Confident in handling it yourself and low maintenance with uncertain horizon: look up an online bank that offers ETFs such as IWDA (accumulation (dividend is not payed but reinvested) or income(dividend is payed out)) and maybe a few more specific ones then buy and hold for at least 5 years.
Confident and high maintenance with long horizon: maybe stock picking but you'll probably never be able to beat the market unless you invest 10's of hours in research per week. However this will also cost a bit and given your initial amount not advisable to do.
Some additional advice (personal):
Be sure that you also have a VERY close look at the prospectus of an investment (especially if you go with a (retail) bank and they "recommend" you certain actively traded funds). They tend to charge you quite a bit (yearly management fees of 2-3% (which is A LOT if you are eying maybe 7%-8% yearly) aren't unheard of).
ETF's such IWDA only have for example a yearly cost of 0.20%.
Personally I have one portfolio (of many) only consisting of that ETF (so IWDA) and one global small cap. It's one of the best and most consistant ones to date.
In the end, the amount you start with doesn't really matter so much as long as it's enough to buy at least a few shares of what you have in mind. If you can then increase your portfolio over time and keep the expenses in check, compounding interest should do the rest.