Someone struggling to learn the basics of wallets will definitely be swallowed by the encyclopedia of Ratimov. What Op needs to do is to take a step at a time. Also they need to have a track of what they have learn and what they have to learn. Whenever newbies claim they have invested, you do not have any evidence or any reason to prove them wrong. So, we believe they have invested and learnt the basics of investment. So many of the newbies make hasty investment, but it pays to learn before investing to earn.
You can learn first before investing or invest while learning especially if what you're investing in is Bitcoin. Investing in Bitcoin is so simple that you don't need someone's to walk you through everything, all you need is where to get the Bitcoin, where to store them and if you didn't use the right wallet in the beginning, you can always adjust to a more secured wallets as you gained knowledge on wallets. Nobody actually knew everything about bitcoin before they made their first investment. OP can learn gradually as he has registered on the forum and all the information are present here also when you don't find them through searching, OP you're free to asked questions as you did and good samaritans that are numerous on the forum will always help you out.
I was able to go through few books about bitcoin, articles and links sent here as guide in the forum. One of the best, I have come across is learnmeabitcoin.com. I don’t know if there is any easier one to learn from and understand than this. After all this, I am still yet to understand the concept of open/closed wallet, software/hardware wallet, online/offline wallet. I keep getting them mixed up whenever I try to have a grasp of them.
The meaning are directly in the names, (example, offline means offline and online means active on the internet). Seeing the posts above me have done justice to your questions I won't bother going into much details but just give you the simplest advice. No wallet is safe from hackers as it all depends on how secure you're because using a hardware wallets and still been careless with your private information can put your coins in the wallet at risk and the same goes for every other wallets. As you're a newbie I'll recommend you start with using Electrum Bitcoin Wallet, it ticks every box of been a perfect Bitcoin wallet except the fact that it isn't a hardware wallet but that's find.