Yes it is absolutely necessary for us to carry out some research when we are choosing any platform we are interested to trade on , base on my understanding there are a lot of platform who are not really interested to help a trader to progress in the trading market but they are just interested in scamming, There are so much of such platforms all over the internet and we have to be very careful about them , carrying out s proper research to understand any platform you have in mind to use for your trading is very important.
If you are not able to carry out a proper research about a particular platform having a good expert to guide you through on how to choose the best platform will always save you the stress of losing your money to a dubious platform.
About from its legitimacy there are certain things you have to look for when choosing a platform , a platform you are using for trading must be able to provide you with correct information of how the market is on daily basis to help guide you on how to trade safely.
They must also provide an educational video tutorial to guide you on certain things especially risk management.