In GO site some feature are supported more and this is also required for making the GO PDFs look nice. Main one here is Latex which can be accessed from the "fx" button in the toolbar or if you are already familiar with it (most Good colleges do follow Latex) then you can simply type latex content with in \$\$. Some other points are
 Do not use subscriptsuperscript option. This is only for naive users. Others can use Latex like \$x_n\$ or \$x^n\$ which will be rendered as $x_n$ and $x^n$ respectively.

For images you can take screenshot of the actual source or draw in PowerPoint and upload them. For graphs (for DFA and others) you can use this site.

For tables, there is a Table option in editor. Table border can be hidden by Rightclick on the created table  Properties and then make Border 0.

Never use space for aligning  instead use Tables.

Never user subscript/superscript  they are for naive users. Instead type \$x_2\$,\$x^2\$ which will render as $x_2$ and $x^2$ respectively. These are latex commands and render nicely. For multiple chars do with {} like \$x_{small}\$.

For equations also use latex. There is fx button in the editor which is useful if you do not know Latex commands.

Most symbols can be used just by typing the symbol name preceded by "\" like \sin for $\sin$,\log for $\log$, \alpha for $\alpha$, \delta for $\delta$, \Delta for $\Delta$,\theta for $\theta$, \Theta for $\Theta$,\sigma for $\sigma$,\Sigma for $\Sigma$, \sum for $\sum$,\implies for $\implies$, \because for $\because$,\therefore for $\therefore$,\forall for $\forall$, \exists for $\exists$, \times for $\times$, \to for $\to$, \subset for $\subset$, \neq for $\neq$ etc.

Some of the other useful symbols are \vee for $\vee$, \cup $\cup$, \cap for $\cap$, \wedge for $\wedge$, \neg for $\neg$, \; for single space, More symbols

For options (A, B, C, D) in MCQs, use numbered lists and then right click> Properties > select Upper Alpha Style.

Even for any other lists either use the Bulleted List or Numbered Lists from the Editor.

Use fx for whole equation and not just for symbols  i.e., use like $n^{th}$ and not n$^{th}.

In fx \sin, \cos, \min, \max etc. are to be used for math function names.

In fx, to get space we can do \; or type inside \text{my text}. \quad. \qquad can be used for extended space. But use this only when strictly needed.

Try to avoid > and instead use $:$ or \implies. Also instead of A) try using A. or (A)

For numbering any equation you can use \qquad \to (1) which should give $\qquad \to (1)$

Anything between $$ is taken as equation (fx). So, to type \$, do enter \\.$

For C and SQL codes one can use the <> option in the Editor. It supports alignment with tabs and does syntax highlight. After selecting a tab size please use CTRL+Z to restore the previous alignment.

Install Grammarly browser plugin to ensure your sentences are grammatically correct.

To align equations using Latex you can also use \ begin{align} ... \end{align} environment inside \$\$ or \$\$\$\$ and align using '&'. For example:
\$\$ \ begin{align} \text{Total} &= n + (n 1) + (n  2) + (n  2) +\cdots+ 1\\&= \frac{n(n+1)}{2}\end{align}\$\$
will be rendered as $$\begin{align} \text{Total} &= n + (n 1) + (n  2) + (n  2) +\cdots+ 1\\&= \frac{n(n+1)}{2}\end{align}$$
In GATE Overflow we make use of MathJax library for Latex. So we do not have the full feature of Latex, but it supports whatever we need. You can see here for more nice Latex options.
For quick start to learn Latex completely any do your reports and thesis in Latex, please see https://www.sharelatex.com/learn/Learn_LaTeX_in_30_minutes
Some common mistakes while using Mathjax
 Using \sum – $\sum$ for \Sigma – $\Sigma$
 Should never write x \$ + \$ y. It must be \$x + y \$ (Symbols and equations together)
 Should not write large sentences under \$\text{} \$. It must be used only for a word or a couple of words maximum.
 \$\mid \$ must be used for $\mid$ split and not  because that automatically adds the required spaces around