Are there any punctuation, grammar, word/conjunction errors? and why?

Using a graphing calculator could be a complex task. Since, most people don't use it. It has so many buttons. However, it has many features that most common calculators do not such as creating a programme, plotting graphs. Here is a quick start guide on how to use the graphing calculator: You need to turn it on-by pressing the "on" button on the bottom-left corner of your calculator-now you will see a blinking cursor on the top-left corner of your calculator. Now you can do a simple math operations you like. In order to plot a graph, You will need to input an equation by pressing the "Y=" button on your calculator, then type in an equation you want to solve. Press the "graph" button and you are good to go.

Using a graphing calculator **can ** be a complex task. **M**ost people don't use** one**. It has ~~so~~ many buttons. However, it has many features that most common calculators do not** have** such as creating a programme** and** plotting graphs. Here is a quick start guide on how to use **a ** graphing calculator: You need to turn it **on by** pressing the "on" button on the bottom-left corner of your **calculator. Now** you will see a blinking cursor on the top-left corner of your **calculator's display.** Now you can do ~~a~~ simple math operations ~~you like~~. In order to plot a graph, **y**ou will need to input an equation by pressing the "Y=" button on your calculator, then type in an equation you want to solve. Press the "graph" button and you are good to go.

https://my.hrw.com/math06_07/nsmedia/tools/Graph_Calculator/graphCalc.html