True as you say for beginners it is better to invest in the top altcoins because the risks we face are lighter and easier for us to predict, then in the top 10 coinmarketcap is the right choice but you also have to look at the potential of the coin to make it easier to make a profit.
yes it is alright to invest with top alts and then hold but so far btc was the easiest investement you can buy it from everywhere