If you use any search engine and type in the phrase "How to become a successful short term trader" or anything similar, you will find roughly 70 million(!) websites that will help you in achieving that goal, or so it seems. While in reality, there's only one right and honest answer which is more like this: "There is an extremely low probability you will ever be successful in short term trading, and you will most likely lose all funds in your account".
This is the 'little' secret known by all retail brokers around the world. They see the actual numbers, they can tell and have admitted in many research reports: somewhere between 95 and 99% of all short term traders lose money and finally have to give up on trading. There is a constant stream of funds from suffering home retail traders to several other parties.
Who are they? Think of: misleading advertisement of signal services, the make-believe easy money program, talking heads on tv surrounded by commercials, the one-click trading app, the trading courses that will make you a profitable trader in a day, make-believe traders in Ferrari's posting on Instagram all day selling useless services, the laptop on the beach money machine subscription service etc etc. But on the bearish side too, there are brainwashing doom and gloom preachers, bitcoin craziness, gold-bugs preparing you for the end of the world, pushing useless products and services.
You can call this the whole crazy circus which is built around the retail trading industry. These parties are not trading themselves, they are safely on the sideline selling all kinds of products and services to newly starting traders. And maybe, just maybe some of them could actually be of good value. But the problem is, there's usually no way of telling and they are mostly a huge obstacle in getting a clear realistic view of the markets.
And even then, once you have cleared out all that mess, there's 'someone' else, ready to get your money: the professional trader, well educated, hyper-motivated, working long hours, constantly adhering to strict rules, doing hard work with an unparalleled iron discipline.
Most traders have the idea, encouraged by the crazy circus, that trading is easy. This is probably why most of them start out with too much trading volume, taking too much risk, making too many trades, etc. If you look at it this way, then maybe we should change that line from the first paragraph and add an extra couple of words, making it like this: "There is an extremely low probability you will ever be successful in short term trading, and you will most likely lose all funds in your account, before becoming successful".
Increasing your chance of success means that while you're learning to trade you should allow yourself to make mistakes and learn from them. Experience the emotional effect of failure, of losing trades as well as winning trades, but make them with the smallest amount of money possible. That way you can make many mistakes while not going broke. Keep a detailed trading journal, collect statistics and try to learn from that. For the time being, disregard trading fees, just look at the trades themselves. It takes time to get the proper mentality and at the same time get rid of a big ego that prevents quick adaption to ever-changing market circumstances.
Then, if you're one of the very few fortunate enough to be consistently profitable in trading, only then it is time to slowly increase your trading size. If success does not hold on, immediately reduce trading size and start over. Difficult yes, very much so. Impossible no.