I'll write some brief suggestion on how to improve your map. This may become difficult to read as the word length grow, but I'm sure it will help you if you can fully understand what I wrote.

You current map have 3 major weaknesses that stops you from ranking it.

1. The patterns are too dull, undiversified and not interesting to play with.

To improve in this aspect. I hate to say it, but it is to play more maps and read more patterns. Just like learning beautiful expressions and techniques from books to improve writing skills, it is the same for mapping.

You can start from this map https://osu.ppy.sh/beatmapsets/1037725#mania/2169455 . It is a relatively simple music to understand its structure and composure. However there are several things you should keep ask yourself when you read it.

What kind of feeling can this way of patterning express? Does it match with what the music is trying to express?

Why it is a double (双押), or a triple (三押) for some sounds, and why some only deserves a single (单押)?

Why the LN (Long Note) appeared here but not there? What can LNs also do other than to express typical sounds?

I really hope you can find out the answers of these questions by yourself. I don't really want to explain further because firstly I may not have time to do detailed explanation, secondly it's MY personal understanding of mapping and it might not be the best.

2. The sounds / The music is not being expressed properly.

I see you separated the music into different parts in the editor using blue lines. You should also try to tell the player "it's a new part" using the map.

Let's use your map as an example, before 00:11:497 and after 00:11:497. The latter part is clearly more intense and therefore USUALLY, mapper will map the latter part harder.

And I see you attempted some changes: 00:11:846 (11846|3,11846|1,12021|1,12195|0,12195|2,12369|2) - It is great, but not enough, especially when you went back using 00:14:637 (14637|0,14811|1,14986|2,14986|3,15160|1,15335|0,15335|3) - later. (If the two groups of pattern looks the same to you. Carefully think about the difficulty of the two patterns.)

The latter music part added more sounds. What exact sounds are added compared to previous music part? I can list some for you: Bass, Kicks, Snares, and many more sound effects. A mapper's job is to choose and express them in patterns. If you map this part the same as last part, then the map can't show the intensity changes / sound changes / additions, and that is what lowers the quality of a map.

3. The difficulty of different parts are not being managed, or purposely given.

This is about trying to understand how hard your map is to play. More specifically, patterns have different difficulties, and to precisely use the harder ones at more intense music parts, easier ones at the contrast, is what make a good map.

Your map as example. 00:51:962 (51962|3,51962|0,52137|0,52311|1,52486|1,52660|2,52835|2,53009|3,53183|3) - and 00:49:172 (49172|1,49172|3,49346|0,49521|1,49521|3,49695|2,49869|1,49869|3,50044|0,50218|1,50218|3,50393|2) -

Do you think they have similar difficulty? If no then which one is harder?

And compared to 01:56:148 (116148|2,116148|1,116323|1,116323|2,116497|3,116497|0,116672|0,116672|3,116846|1,116846|2,117021|2,117021|1,117195|0,117195|3,117369|0,117369|3,117544|2,117544|1) - this?

Or 01:58:939 (118939|3,118939|0,119288|1,119288|2,119637|2,119637|1,119986|0,119986|3) - this?

Use the patterns that are similar in difficulty, if they sounded the relatively same in the music.

Some honest words here. Your map is so far away from rank. No matter how many small changes and mods, they can't fix the issue. From my observation you are also quite far away from ranking your first map.

But please bear in mind, every mapper was once like you, never feel ashamed to ask or to seek advices. The more I look at your map the more it reminds me of how I started mapping, and I believe there still exist some good mappers that are willing to help new mappers like you, because they can feel the same way I felt.

Play more. Map more. Try more mapping techniques. Learn mapping techniques from other maps. Try to mod other peoples map. (Don't be afraid of modding others map, modding is a process of exchanging mapping ideas, not one-way criticizing)

Do those more frequently, and you will improve faster.