Can you suggest me which one is best Altcoin coin hold for 2018? 
I think you should start with Ethereum or Bitcoin if your assets allow. The best are altcoins in the top 10 or top 20 by market cap price. I mean EOS, Ripple, Litecoin, Monero, Cardano. I would choose those.When I started the market I bought Bitcoin, I think that with all the investments in this market, Bitcoin is needed, so buy Bitcoin and find out how it works. Necessary for beginners