Exactly.Invest only in top 10 coins because these will eventually give you huge profits particularly when bull run comes.And having ETH and BTC are really good choices because these two are considered the most potential coins in the market.Keep on studying the crypto market so you will gain more valuable ideas which will mold you to be a good trader in time.
In fact it is the other way around, it is true that the profits you can get out of the top 10 coins are very good but those are the safest coins to invest in the market, if what you are really after are huge profits then you need to take a risk and invest in coins outside the top 50 or even the top 100, your risk will grow exponentially with such coins but at the same time the rewards grow as well and depending on your objectives that could be a good thing or a bad thing.