Coinbase offers a centralized wallet and you only have your public address. If you are holding long term, it is preferable if you are using a cold storage or at least a desktop wallet like electrum or exodus that gives you access to your private keys. You can just leave few of the coins you may want to transact with in your coinbase wallet but not all you have.

Now coming back to your original question. Exchanges won't give you a private key, it will just give you an address to store your Tether. So if you are not planning to trade with a significant volume, you can still use exchange address. But it is not recommended for huge volumes.

You can easily get to trade LTC/USDT pair on exchanges like bittrex, binance or poloniex, without having to register on the tether platform, which I believe should make things easy for you. Here is a step to guide you.

- Open an account on https://bittrex.com or https://binance.com
- Familiarize yourself with the exchange
- Deposit your LTC on any of the exchange address
- Then, you can search for the LTC/USDT pair and there you have it.

However, as a complete noob who wants to trade, I really hope you know what you are doing.

While you probably don't need a Theter wallet, you certainly need a good LTC wallet. If you haven't figured that part out, I recommend using electrum for LTC. Keep most of your LTC locally in your electrum wallet.

When a market is down, people come out of the woodwork to say it's going to zero.  The end is near.  The stock/bond/crypto/whatever is going to zero.  And then when we're in the midst of a raging bull market, the same thing happens except then people think the asset is going to the moon and beyond.  Nothing can stop it.

The truth, in my view, is that market fluctuations are pretty random, and bitcoin is still way higher than it was when I first got into it.  Could it fall even more from its ATH?  Sure, and it might.  The fact is that I don't know, you don't know, and OP here definitely doesn't know--but that never stops anyone from speculating, does it?  What all of us need to realize is that OP (and those like him) don't have some sort of crystal ball that allows them to predict bitcoin prices, or any kind of inside info that would allow them to do the same. 

There isn't any inside information in crypto, because there aren't even businesses underlying any of these coins, like there are with stocks.  Thus prices are driven purely by supply and demand.  Nobody, as far as I know, has the inside scoop on future demand, and we already have all the information we need on supply.  People who say they "know" what's going to happen really don't.  Don't listen to this crapola.

Always is. The market needs people who continually do arbitrage. The principle of the market is that at that time, the price will always be the correct one. For being the price people are willing to buy and sell. But the big thing is that in certain markets prices may be too far apart. This is a profit opportunity and is beneficial to all.

Whether market is rising or falling does not matter...

lets see what will happend with the price 

Would this coins be traded in exchanges?

Be very cautious on that series because they tend to tell the truth under other circumstances.

I am not the problem here. The problem here is hard cash is fading, rapidly. That's just the way of the world right now and Bitcoin is spreading, and if Bitcoin takes over we are all in a world of hell. It is unregulated, it has already reached it's transaction volume maximum, and it is partly controlled by Chinese miners.
With "Ecoin" we control the ledger, and the mining servers, We are the Authority. I will make sure you have visibility into every single wallet that is open, every loan, every transaction, which means we can start building new assets, which means we can start rebuilding the banking sector.