Regardless of why you are learning write scripts a usful tool to know is how to use scripts to rename a large batch of files.
This script is avalable in both bash and python

Bash

#!/bin/bash
count=1
for file in *.jpg; do
mv "$file" "image_$count.jpg"
((count++))
done

Python

#!/bin/bash
count=1
for file in *.jpg; do
mv "$file" "image_$count.jpg"
((count++))
done
It is the end of the semester or you have just finished a large project and your files are in a state, now you want to organise them by extention
Here is a script to help you do that

Bash

#!/bin/bash
count=1
for file in *.jpg; do
mv "$file" "image_$count.jpg"
((count++))
done

Python

#!/bin/bash
count=1
for file in *.jpg; do
mv "$file" "image_$count.jpg"
((count++))
done
It is recommended as keep a back up of your files, I have first hand experience on why you should do this.
Here is a script to help you achieve that.

Bash

#!/bin/bash
count=1
for file in *.jpg; do
mv "$file" "image_$count.jpg"
((count++))
done

Python

#!/bin/bash
count=1
for file in *.jpg; do
mv "$file" "image_$count.jpg"
((count++))
done