Increase Celebrity

Open up the cheat console by pressing Ctrl+Shift+C.
Type in testingcheats true and hit enter.
Shift+Click a Sim to open up more options.
Go to 'Public Image' to adjust the celebrity level, reputation or change fame quirks.
Click on 'Increase Celebrity Level' to give them an extra star

I normally Give them the UnstoppableFame aspiration reward trait (that is earned through the 'World Famous Celebrity' aspiration) with cheats so I don't have to worry about it decreasing as I play, lol.
You'll get the extra fame point that normally comes with it when you earn this trait the hard way though.

Open up the cheat console by pressing Ctrl+Shift+C.
Type in testingcheats true and hit enter.
Type in Traits.equip_trait UnstoppableFame
(You'll have to do this with each sim you wish to have this trait.)

Use testingCheats on, shift-click the Sim, and use the Public Image menu. (According to Carl's Sims 4 Guide. Don't have Sims 4 running right now, so I didn't test it.)

How do I see their reputation?

"DeadFishy;c-17354862" wrote:
How do I see their reputation?

are you talking about the Sims' control panel which shows traits and stuff?

I’m not sure. I’m not sure how to view a sims reputation

"DeadFishy;c-17354865" wrote:
I’m not sure. I’m not sure how to view a sims reputation

the Simolgoy button is 5th icon to the right after the aspiration for your Sim