My first note

The day today was incredibly beautiful, my best friend is the most beautiful in the school.
In the afternoon we play soccer, she is  a very good player.
With her, my day is the best of days.
The love for all that is.

Notes: "In the afternoon, we play soccer" implies that soccer is played every school afternoon.

If you wanted to say that today we played soccer, you would say "In the afternoon, we played soccer".

I am not sure what "The love for all that is."  is trying to convey.

Perhaps "I love her for all that she is" referring to your girlfriend.

I have added "of days" as that is more English like.

You could also say "My day is  best when I am  with her"