Hey there mama430,
Thanks for reaching out to the Apple Support Communities.
To get started, if you go into Settings > General > Keyboard, do you by chance have any Text Replacements set up that may be causing these automatic changes? If you do, try removing the text replacements shown, and test the issue gain.
For more details, and how to check these settings, check out this link here: Save keystrokes with text replacements on iPhone - Apple Support
Have a word or phrase you use and don’t want it corrected?
1. Go to Settings
> General > Keyboard, then tap Text Replacement.
2. Tap
at the top right, then enter your word or phrase in the Phrase field, but leave the Shortcut field blank.
If you don't see any Text Replacements set up, it may be helpful to try resetting the keyboard dictionary as well. This will remove all custom words and shortcuts, and the keyboard dictionary will return to its default state, which may be able to help with this particular issue.
You can find these steps under the "Reset your personal dictionary" section in the same link above.
Keep us updated on the results.
Take care!