If you would like to download a LaTeX distribution and front-end/compiler to your laptop, try:
A simple visual editor for writing diagrams and converting it to Tikz github.com/yishn/tikzcd-editor, try it out at https://tikzcd.yichuanshen.de
For access to past journal articles that are not freely available online, you can search on JSTOR:http://rdl.lib.uconn.edu/databases/1009;go (for this link UConn ID is needed).
Wikipedia:Manual of Style/Mathematics
Advice on Mathematica Writing by Keith Conrad
Examples of proofs by induction by K. Conrad
Math students, connect with prospective employers here: MAA Career Resource Center
Use CamScanner app or another scan app to scan your hand-written homework into PDF.