If you are a beginner, then you do not need to trade anything except bitcoin. Experienced traders can determine the perspective of some coins and make trades with them because some altcoins look quite interesting in the long or medium term.
Just because an altcoin looks interesting does not mean its worth putting your money in. Where does the interest come from? Take every whitepaper and roadmap prepared with a large punch of salt (LOL).
Not only are they always misleading into investors trusting them but they will change them from time to time for their own benefit or delay releases just for the sake of it. If interest is coming from the price pump be very careful what coin you are jumping into because transient pump and dump are normally happening in every coin and they might wash you down during the dump.