When you format your posting to retain the spacing (like for program code), you need to use the Code button.
Please try to make the title more meaningful.
If you have multiple questions, you should start more than one topic, especially when the questions are on different subjects.
With your first questions on Cobol, you really have to get back to a very basic level of understanding.
77's have to be at the start, before any 01 level. If you try to put them after an 01, you will get a compile error.
For your two-dimension table, just use a level number that is greater than the one with the first OCCURS.
05 filler occurs 10.
10 filler occurs 10.
15 this-two-dimension-item PIC X.
is one way of deining it.
For your RENAMES example, you have to understand that higher level numbers define the storage for a group item, and a group item cannot therefore have a PICTURE clause.
I have never used RENAMES. I don't suppose you'd genuinely ever need to either.