Fix 3D model for 3D print

My 3D print model fails to print correctly. The print gets to a certain point, then the print shifts. This is possibly due to the high level of faces used in the .blend model. When this model is printed at 5cm (total height) it prints fine, yet at 13cm it fails with the result shown below

The model will be printed at 13cm, so the detail needs to be okay the best that can be achieved for that size.

I require:
- The 3D model (.blend) fixed so that it prints correctly. This likely requires dropping the detail, to reduce vertex and faces and then exporting as stl, but I am not familiar enough with blender to do this.
- A 3D print (stl format) to print that will work successfully with my FlashForge Adventurer 3 printer
- Improve the text on the front, so that it is smoother and clearer. The text reads "Melbourne 2024" but is jagged.

Payment for this project will be after 2 days when the successful 3D print has printed.

I can email the files, but to upload here was a 10MB limit here. The Zip of all files comes to 22MB

If you know what you are doing this could be 10 minute job.