Create your checklist of what you want to achieved in the Bitcoin market, most people will just jump to any site you're introduced to and buy coins after a while you discovered you cannot have access to the site's. Many have lost their wallet for careless and impatient to learn, when someone introduce something to you, first of all do a proper research of that site, learn what the site is all about.
Try not to rush investing your resources first check your list of interest, ask questions and follow your mentor amicable, don't try to be too smart to outsmart he or she. Me I have several lost experience, this piece of advice will guide into crypto journey
The topic title is about trading, the content seems to be more about investing. You seem to be somewhat lost in terms.
Trading is not for newbies. Most newcomers will act like in gambling and, like in gambling, most will - sooner or later - lose money.
Investing is easier, but as you mentioned, one has to understand what he's investing into, understand the specifics (for example Bitcoin price can have wild fluctuations, or investing in Bitcoin can easily mean it'll take years until you'll be on profit; for example altcoins were at least for me always unprofitable for long term), understand where to acquire the coins from (not all exchanges/businesses are legit) and understand how to store those coins (safely generate wallet or use hardware wallet, safely store private keys/seed words, withdraw from exchanges). Plus, he/she has to learn patience.