The atmosphere is cleaning and the smell of soil and grass makes me feel calm.

The word "clean" is an adjective of the atmosphere. THe word "cleaning" is a noun as in "I have cleaning to do." or "I have to do the cleaning." It is also the present tense of the verb "to clean" for example, "I am cleaning the dirt off my shoes."

The wind is now warm now, so I dwon't need to shiver with cold anymore.

We can stylistically choose to place the adverb "now" at the beginning of the sentence "Now the wind..." or also after the primary adjective describing the wind as above. Stylistically we try not to use "now" immediately after the verb as it is easily mistaken for the word "not". I chose to use a comma to separate the two clauses of this statement. THis is optional, but I like to give a space to understand the thinking process of the speaking. English is more direct; the verb "will not" is sufficient.

After this rain today, I expect that manye roses will come outbloom in all their splendidly.or!

I've added the word "this rain" because it is the reason for the expected roses. I changed "come out" to "bloom" and changed the adverb "splendidly" to "in all their splendor" because the word "splendid" describes the quality of the roses, perhaps the result of blooming. However, your use of the adverb "splendidly" is correct and also acceptable.