The two actions you have are not the ones you want to use. You are not using a PowerApp (per your description), and you have no script (per your description).
From what it sounds like - please correct me if I'm wrong - you have created a single Excel spreadsheet. You have column 1 and column 2 as First Name and Last Name, right? Now you want to - for each of those rows - get it, and then query Active Directory to fill in the rest of the details (such as Email address.)
So, Step 1 - ensure the content in your Excel spreadsheet is formatted as a Table. Also add the columns where the other info (email, department, etc) will be entered. I'd recommend also making "FullName" that combines First Name, space, Last Name. Save and close the file.
Step 2 - create a manual trigger, if you're only firing this when you want to, not based on a schedule or automatic happening. New Flow > Instant Cloud Flow > Manually Trigger a Flow. It's a blue button with a white hand pressing a button.
Step 3 - List Rows Present in a Table. Point it at your Excel sheet, and your Table.
Step 4 - Search for Users - use dynamic content (click on the field, you'll se Dynamic Content and Expressions appear in a little tabbed box) and then select FullName from the Excel section. It'll turn into an Apply to Each, and that's okay.
Step 4 - Now that you have the UPN from that search, you can use Get User Profile. Use the output from the Search for Users. That will also turn into an Apply to Each since it doesn't know if you have 1 or several users. That's fine. You can use the names of the properties held in active directory (such as department, workemail or email, whatever your organization uses, delimited b y commas.)
Step 5 - Now you have that info, you can cram it back into Excel by using the Excel "Update a Row" action. You will need a unique key for this, which luckily, FullName SHOULD be. (If it isn't, you need to make one - it can be FullName+the Row ID or something). You're going to point back to your same spreadsheet, but the "Key" will be the name of the column (FullName) and the "Value" will be the actual FullName. Then, once you've done that, all of the fields in your Table will appear and you can drop the Dynamic Content output (from Get User Profile (V2)) into each, as it applies. (Ie, Department into the Department.)
WHen you run this, it will run for each row entry.
This is not a beginner level task in Power Automate. It's like, somewhere between Beginner and Advanced, closer to Advanced.
