Is there a template for income and expenditure (personal finance)

I want to have a spreadsheet to monitor my finances

You’ll get a more reliable result with a dedicated application like GnuCash (free & open source). Other applications exist as well.

Search the template site with keyword “Finance”. With any luck, you find something suitable. Also try other keywords like “personal”, “economy”, “ledger”, “accounts” etc.

Note that spreadsheets are inherently “free-form” tools, so even when steps have been taken to ensure data integrity in the templates, there is a risk of error due to flawed entry, copying or moving of data. A spreadsheet is a powerful tool. Just like for other power tools, you must know the basics of your tool to work safely. Check that the figures are sensible. If something surprises you, check again.