3.1. If you want to transfer and forget, you can try some of the RoboAdvisors, which will buy ETFs/Bonds for you with assigned percentage. I personally use ETFMatic [1] for couple of years without any issues.
3.2. If you want to buy ETFs by yourself, you can open brokerage account. As I read that you are from Europe, we mostly use Degiro [2] or IBKR [3] here. I use IBKR personally. You will be safer with ETFs, rather than single stocks. One of the recommended ETFs, would be VWCE, which Tin short - tracks World economy. As my colleagues say, VWCE and Chill.