Gdtyjr

I have seen some nice functionality in the the latex files of certain math journals and I want to create that functionality in my own .tex file. Right now, I can write

beginequationlabeleq:STUFF
MATH STUFF
endequation

and this will produce a numbered equation. Elsewhere, I can refer to "Equation refeq:STUFF," and it will take care of the numbering for me. Here is the new functionality I am looking for: I want to be able to write

begintheoremlabelthm:LATEX
For example, this theorem is Theorem 2.5.1 because it is the first theorem in the fifth subsection of the second section.
endtheorem

I want to be able to write "Theorem refthm:LATEX" and have my PDF build with the numbers for the theorem's number in this format: [Section].[Subsection].[Item], in this case "2.5.1."

I also want to be able to toggle the numbering for unnumbered items such as a simple remark, or

beginproof
Proof of the above numbered theorem.
endproof

where I would refer to this as "proof of Theorem refthm:LATEX" and I would not want the item counter to count the proof, so that the item following the proof would be item "2.5.2"

BELOW FIND MY TEX FILE WITH THE NOTES ON WHAT I WANT:

documentclassreport
usepackage[utf8]inputenc
usepackagegraphicx % needed for figures
usepackagebm % for math
usepackageamssymb % for math
usepackageamsmath
usepackagegraphicx
usepackagetitling
usepackagebigints
usepackagemathtools
usepackagecenternot
usepackage[left=1in,right=1in,top=0.468in,bottom=.768in,centering,includeheadfoot]geometry

titleLARGE textbfProof of Latex

authorLargeHodor P. Bojangleton

begindocument

renewcommandabstractnamevspace-baselineskip
datetoday
maketitle

tableofcontents
newpage
large

sectionSECTION 1

Currently this starts with 0 because it is counting the chapters, but I only want to use sections and subsections. I need to get rid of the counting for chapters.

Items in this space should be numbered 1.0.X

Here I create and equation with the "begin/end" syntax that I want for my new commands.

beginequationlabeleq:111
1+1=2
endequation

I want to add a zero for the subsection in the numbering of Equation refeq:111.

subsectionSUBSECTION 1.1

Here we have the 0 chapter number than I want to get rid of.

Items in this space should be numbered 1.1.X

I want the item name and number to appear aesthetically like:newline

noindent Large textbfTheorem 1.1.1 After I write "begin theorem" to mimic the "begin equation" functionality that I already have, I want the text I write between "begin" and "end" to show up on the same line as the large bold theorem header.newline

noindent Large textitProof. This is an unnumbered proof of the above theorem.newline

noindent Large textbfLemma 1.1.2 The item counter did not increment for the proof.

sectionSECTION 2

Items in this space should be numbered 2.0.X

subsectionSUBSECTION 2.1

Items in this space should be numbered 2.1.X

subsectionSUBSECTION 2.2

Items in this space should be numbered 2.2.X

enddocument