What you are looking for is a product called "Speakerphone" from "Audioease". This has some basic room reverbs and also device impulses. Additional - more expensive - options are "Altiverb" and "Indoor" - also by Audioease.
This is not a specific effect, it is simply the result of the V/O artist's voice plus some fairly standard dialogue mixing effects chains, including de-essing, compression and EQ. Nothing more than that.
The main component of what you are hearing is actually the voice of the V/O artist.
OK some tips to get consistency.
When you think you have done enough practise, do more practise just in case.
In all seriousness, consistency is a learned skill, which you will improve at as things progress.
The best way to pick up the energy and speed for new material is to listen to existing material and re-voice it just to get ...
Consistent voiceover is a learned skill, just the same as being able to record consistently you need to learn to be able to speak consistently.
Your voice will also warm up with each run-through, so don't even try to take the first 3, or they'll all sound different.
Until you're very aware of how your voice warms up over time - & of course, everyone is ...
Yes, you should probably choose the quietest available space to record in.
Set up your microphone in the same position each time. Use the same level settings. Perform the reading consistently. If you're getting popping p's and other breath noise, add a pop filter to your mic. A SM58 maybe isn't the ideal choice for this sort of work, but it'll do!