If you really want to invest in crypto and that too if its first investment, then start with bitcoin. Sky is the limit for bitcoin in the years to come. Followed by ETH.
I agree with you to choose Bitcoin for investment, because in my opinion Bitcoin is the best choice for investment, especially for long-term investments, because the price of Bitcoin will certainly continue to rise and of course will give you profit in the future, then I think investing in Bitcoin has a smaller risk than you investing in altcoin.