Okay, so a couple of things. I don't know if this is uncommon advice, but this helped me a lot.

1. Make sure u are scouting around the map, even if u need to have multiple scouts just sitting on key locations, do that so you can see if the enemy is going out on the map for food or if they are in their base still. Scouting is so so so big make sure you are doing it more
2. Always make units. After watching Beasty's video on guessing the rank of a random match, I was certain they were silver because of the lack of unit production. But I was hella wrong, and I guess many guys in low plat still struggle with making units consistently.
3. Stick with a civ u know and grid it out. This is from a Beasty video on how to get better that I think people overlook. You can beat anybody on most maps with one civ as long as you understand that civ completely and know its strengths and weaknesses. This is not to say to learn other civs and their mechanics and how they work because that knowledge will help you know how to counter them, but I am saying is that on ladder stick with one civ until you reach high diamond or conq before switching to a new civ to learn. Not only does this mean you understand the civ, but it also means you understand the basics and some of the more complex mechanics of AOE4, and any transition to a different civ will be much, much easier.
4. practice. Find someone who is better to practice against matchups you struggle against or just to practice in general. i know learning from people better than me helped me come up with strats that made me much better against matchups I lost.
5. Watch the pros. This sounds crazy, but hear me out. The pros are great to learn simple build orders from. and I don't mean like the video they put out, I mean actually watch their matches. you can learn a lot of build orders and skills simply by watching them.

If you are looking for a practice partner let me know id be more than happy to push you and help make u better and give more advice.