I need some advice, I had some crypto a few years ago and then sold it and made some good profits and I am now planning to buy some crypto once again and I admit that I am outdated on the crypto world right now. Can someone give a brief explanation of what DeFi is and what are your top 5 coins/tokens and where do you usually trade it. Thanks! 
Try to Check Polkadots here >>>> https://coinmarketcap.com/currencies/polkadot-new/or try to check Cardano here >>>> https://coinmarketcap.com/currencies/cardano/
But if you are tending for long term Holding again like what you did last time ? then Maybe you should consider Litecoin and Binance Coin .
and if you can take a so much risk but with a good promise of income ? then this should be Ripple >>>> https://coinmarketcap.com/currencies/xrp/
But of course trade at your own risk , We are here to advise but it is your money to concern .