As much as I would agree Crypto assets are high risk / high return, Cardano included at the moment – to compare Cardano to casino chips is very naïve, they probably have that opinion on crypto itself, not Cardano specifically, which to be honest can be quite hard to convince someone otherwise.
Cardano still has a fair way to go to achieve its roadmap, although things are moving along nicely now and we will be there quicker than some people think.
For someone to get into crypto they need to make their own decisions and satisfy themselves. The crypto space gained a reputation for scams, pump and dump schemes and something used by criminals. There needs to be a blockchain which breaks away from this and gains its own reputation; which it will not do just through telling people what the projects intends to do, but only by doing it and showing people. Cardano isn’t a hype project; I would say at this stage, unless someone does research into Cardano, it isn’t easy to get new everyday people on board. – Things will change one day.
If your friends are genuinely going to give you a chance, and you want to give them the knowledge they need to make their own decision, whether to spend their hard earned cash on Cardano or not, I would start with the famous Charles whiteboard video.
There is no one better than Charles Hoskinson at convincing someone on the potential of Cardano, I recommend checking out some of his videos on his personal youtube channel.
For some very good short videos explaining specific things within the Cardano space, adatainment is a great source of easy to understand information
IOHK are also putting out video updates explaining where we are at with the Shelley Testnet
The https://cardanoroadmap.com/en/ is a good place to visit to read papers and see the different stages for the current roadmap of Cardano.
Finally, Cardano has three entities – EMURGO, IOHK and the Cardano Foundation – it is good to look into these and research what each of these entities do. Hopefully some of this information is a great source for you and your friends to get started.