I have played about 400 games of 1v1, but I feel my 1v1 is very bad. I seem to be full of loopholes. I can easily lose my ACU or army or mex. Who can tell me how to play well in 1v1 and what are the core rules of 1v1? How do you achieve the optimal balance between economy and military?!
Which ELO do you have?
What have you tried so far to get better?
If you watch the replay and just redo what your winning opponent does you usually get easy to ~1200+
No idea if you can even access Discord in China but if you can, there is a training channel at https://discord.com/invite/hgvj6Af where you can post a replay and have trainers help you out.
If you haven't read my guide yet, (https://forum.faforever.com/topic/766/ladder-1v1-beginner-intermediate-and-advanced-topics-by-arma473) you might find some interesting idea or a different way of looking at the game.
At your level, you should probably find a trainer who can give you personalized attention. If you can play a competitive 1v1 with Bennis or Harzer, somebody telling you a few slogans about the "core rules" isn't going to help you.
Zock said the way to improve is to go into every match with 1 idea about what to improve for your gameplay. So you are always improving a little bit.
Blackheart also prepared a list of ideas about how to improve. https://forum.faforever.com/topic/1222/how-to-improve-forever-6-laws
I just watched 2 games of you against plat. In both games you lost because you had a smaller army at the t1 stage.
This was partialy due to a bad build order. You were floating 800 mass while having only 4 factories. This usually means gg. Generally when having as much mass in the bank as in land units a couple minutes in you messed up your bo so hard you can consider ctrlking. But having a better ecomanagement is easier said than done. Babysitting your eco bar and training yourself to feel horrible when your massbar is full is my way of improving on that.
Also you went very greedy on the t2 mexes, while being down more then a factor of 2 in army size. General rule is that you only do long term investments when you are at least even on map control/ army size.
In terms of improving you could try out what it feels like to run yourself dry on only t1 landspam. That is smth that I'm also doing to learn how to crush at the t1 stage. It won't get you to 2k (unless you are called espi) but it will show you how having a bigger army helps and where the limitations are.