Another way you can invest is day trading, which is a trading strategy where investors buy and sell orders for multiple times in one day. This requires more knowledge and skills. I suggest you use a demo account.
I would not recommend a beginner to go into day trading. There is a huge risk involved, any you have to pay transactions fees every time you trade, plus taxes (depending on your country) on top. Your recommendations about just buying and holding is probably the best strategy in my opinion for new people.