"Repair" sound

Hi, im trying to make an engine sound for game. And, it’s not going very well. Maybe because im completely green in audio editing. I’ve done by myself one sound, and i can’t really do next one. I want to “normalize” sound or something like that. Just that the sound does not stutter and be smooth in the same tone. I just want to know how to do that (if it is even possible).

My sound to do is named: ACTUAL.wav

Original sound from game files (what my sound want to look like) is named: GOAL.wav

Audacity 2.2.3
Windows 10 Version 10.0.18363 Compilation 18363

To make a loop “smooth”, the start and end need to match up, like in this sample.
If you load this into Audacity and apply the “Repeat” effect, you should find that it plays without stuttering.

There are some tips for making loops here: https://manual.audacityteam.org/man/tutorial_looping.html