Advice on where to invest my child trust fund.

Hi everyone so im turning 18 soon and I will have access to my child trust fund there is about £8,000 in there and I am wondering where I should invest it. My dad who saved all the money for me told me to spread the money across various things like premium bonds and ETF's aswell as putting some in an ISA. He told me its better to spread them so the money is not all in one place and isant a single point of faliure. Just wondering on if you guys would agree and if so what are the safest places to put the money for a young inexperienced investor.