Go to dafont.com
Search for a font you like
Click the font name to open its details page
Click the Download button
A .zip file will download to your device
Open your Files app (or Downloads folder)
Locate the downloaded .zip file
Tap it to extract/unzip the contents
You'll see font files (usually .ttf or .otf files)
Tap and hold the font file (.ttf or .otf)
Select Share
Choose Copy to "Fonts" (or a similar option)
Alternatively, you can email the font file to yourself, download it on your iPad, and follow the same steps
Open Settings > General > Fonts
Scroll down to verify your new font appears in the list
Open Procreate
Select the Text tool
Tap the font dropdown menu
Your newly installed font should now appear in the available fonts list
Select it and start typing!