Are you going to invest in crypto? You should learn many things about the crypto. If you are willing to invest with such platform, I think you must be very careful. If you want to invest, you are better to buy Bitcoin. It is a worthy and safe both for long term or short term investment.

I think ethereum is currently still able to survive at high prices because of the influence of the support of the whales and investors who are still on ethereum, whereas if there is a FUD that attacks ethereum then the price will definitely collapse, until now ethereum is still a safe big coin.

 I only have the top 2 coins on my current portfolio list, then the rest are in the old coins which have low prices but have many holders, I won't mention those coins, I think we can learn how Dogecoin can pump up and the holders make a profit

There are lots of other methods used online, like wallets that provides the combination of hot and cold storage for the safe keeping of private key, seed phrase(mnemonics).
To me, the physical storage remains the best and safest amongst all

I use MEW with Ledger.. but Metamask seems great too...common sense will take you a long way here.. just don't get phished or EVER give out private keys.

First of all welcome to crypto world , you can used binance  , huobi  , or coinbase pro as a exchange . You can also used dex exchange like uniswap and pancakeswap.
There is more than 10K crypto currency available in market you must have enough knowledge to select best one for you .
I would recommend to buy top 100 crypto currency as a long-term goal .

The main thing that you shouldn't do in case of a sharp and deep fall in prices in the cryptocurrency market is to sell your cryptocurrency assets at a loss. If you did not manage to fix your profit in time, you need to patiently wait for the next wave of price growth in this market, nothing can be done here. Considering that prices on the market have been constantly growing over the past six months and even in the current state are still high compared to November last year, so far there is no particular reason for concern.