Every DBA should have a toolkit. A set of scripts that you are comfortable with and can reuse over and over again.
If you don't, then where do you start in building this toolkit.
Now there are a lot of scripts available for download, but you want to be sure that any scripts come from a reliable and reputable source.
I would recommend the following as starting point.
1. Ola Hallengren's SQL Server Maintenance Solution
The industry de-facto standard for backups and maintenance. It is by far the most complete and thorough set of scripts for ensuring that your databases are backed up, error free and optimised.
You can download the free solution from his web site. https://ola.hallengren.com/
2. Brent Ozar's First Responder Kit.
A suit of scripts for getting a handle on your SQL Server environment and then finding configuration issues and using all this for performance tuning.
3. SQL Down Under
Tools for comparing databases, tables, finding unused indexes, manipulating strings, performance tuning and converting data.
4. SQL Skills
Anything from SQL Skills is gold.
Get familiar with these scripts and you will have the start of a good toolkit.
You can supplement this with anything from Adam Machanic, Glen Berry and Kalen Delaney just to name a few.
You can then add your own scripts over time.