I came in contact with crypto currencies after I joined steemit. At first, it worse than Greek and Latin to me. I even asked my country's exchange to just convert crypto to fiat for me but they declined. So, I started to convert steem and SBD to crypto and then sold it on my local exchange. After the first few days, I got the hang of it but it still took me months to realize that I should have invested in steem rather than cash out. HODL is a better option when it comes to steem because steem gives you returns for the investment.
The crypto prices started falling heavily but luckily for me, I had invested in BCH or bitcoin cash which did not fare badly and thus got me a fair price.
I later invested in steem when it was 3. something US dollars. It has fallen since and did not recover but I believe in steemit and hope that I will be able to cash out my investment and a small profit too.
Many people have almost given up on steemit but steem based applications like musing.io and steempress have given us hope.
I hope the price of steem rises.
As for investing in other cryptos and selling, it is better to follow the instructions of very wise and experienced traders whose posts you will be able to read anytime by clicking the related tags on steemit page.