You can easily export the participants of an event into a spreadsheet, in the Participants module. There, select all the participants you wish to export, click on Actions menu (3 dots), and select Export.
You can (un)select and reorder all the fields you wish to export in the spreadsheet as well
A download bar will appear at the top of the page - when it says 100% completed, click on the download button and your file will be saved onto your computer.