First, you need to decide what kind of trader you want to be, you want to invest longterm or not?
use coinmarketcap to check tendencies but read and read a lot, get information about the project behind each coin and who is involved and potential investors, that could help doing some choices! 

The only risk if you hold it is to lose, of course.
Like any investment!

Well it really depends on your personality, if you're more mainstream you might want to try Ethereum, where you can invest in different ICO's and tokens right now and where you need to be really active but if you're more like a longterm thinker and don't want to be trading so much right now you could start investing in Bitcoin and just hold it there

IOTA is the coin to watch even if its already "big"

My Ether Wallet is always a good option for Altcoins

Join Telegram groups, most experts, and ICO founders share their info there! is the best way

IOTA definitely!

It's one of the coins that can actually break the barriers of Ethereum

https://www.cryptocoinsnews.com/iota-price-explodes-after-microsoft-partnership-announcement/

Here is a really good starting guide: https://thenextweb.com/contributors/2017/08/07/crypto-pr-publicize-blockchain-startup-successful-ico-beyond/