Slightly tells me that I know bitcoin from this forum around June 2017,
But I haven't kept up with the crypto world for a long time due to my busy business and boredom with the price of BTC in 2019.
So I almost forgot all my assets until there was one. the thing I think is my stupidity, I omitted my Trezor which still contained around 9 ETH at the time I bought ETH around $ 700 in mid 2018, and ETH keeps dropping so I ignore it.
Long story short I want to start from scratch I want to ask the seniors who are here.
I want to start trading again. Could you please give me some advice so that I don't go through things like a few years ago.
It was unfortunate that you have lost your trezor which contains the crypto you bought years ago. I hope there's a way you could stumble upon to recover your seed phrase at least to open your account again. Because 9 ETH is such a big amount especially now that it pumped its way up after several years have passed. But since you have mentioned that you want to start from scratch, I assume you are now ready to let go and forget the assets you bought.
If you will be investing once more in crypto, /just invest what you can afford to lose. you can invest your spare money if you have so that if ever things go bad, you won't be heavily affected. Ask yourself if you want to stay for the long term or short term and from there, decide. If you are here for the short term, then have some capital that you could use to make your money flow in buy and sell. If you are here for the short term, invest in good coins and hold as long as you can and as long as you are satisfied. It's never too late after all to start investing. It's better to do it now than never at all. We can always make up with the missed times and opportunities today rather than waiting to regret once more in the future.