This model is mostly created by hand. Here are the steps I used:
Draw the letters on a piece of paper and scan themor take a photo.
Install inkscape, load the image into inkscape and turn it into vectors by redrawing the letters on top of the image as lines. Delete the image with your hand-drawn design afterward. Save the vector image as SVG.
Create a new tinkercad design and import your SVG. You should get the letters as 3D objects as result.
Now, to get the outer object, you need a thick version of your letters and a negative object of the normal letters. To create the thick version, go back to inkscape and create a copy of your SVG. Now, select a letter and use Path > Outset ( or Ctrl+")" ) one or two times. This creates a thicker version of your letter, not just a resized one. Exactly what we need.
With these steps, you can create the outlines for the letters as you will need them in tinkercad to create the outer and inner shapes.
Hope these instructions help.
To get some inspiration for the Pokemon Letters, search for “pokemon font” on the web.
The author marked this model as their own original creation.