In my opinion the most important thing you do is to diversify. If you want to invest 12k, you should have max 50% in one coin. Myself I have about 25% Bitcoin, 25% DeepOnion, 15% ETH, 10% Link and a bit other smaller coins. With so many coins to choose from it can be hard to know if you should invest or not, but just do some research and make up your own mind. If you simply trust what people here say you might lose all your money and not even know why.