Welcome to the forum, mate!
First and foremost thing, ICO is a totally different concept than Bitcoins, but it is conducted with the use of smart contracts taking many cryptos including BTC and ETH in order to gather investments from participants. If you want to get into an ICO:

• Watch out for the team (do a deep research on their names and snaps as well as check whether they're for real or fake)
• Read the Whitepaper carefully (only invest if you find that there is something that could be worth a change in the niche that they're going to use their tokens for)
• Check for total number of tokens in sale, check for their hard and soft cap as well as try to compare with the breakdown given over their website that is it going to fulfil what they're expecting or not (whether they're asking too much or too less)
• Check if they've taken too much out of the total supply already (eg.: premined)
• Last but not the least, only invest what you can afford to lose