Jennifer,
The more cleanly styled the Word doc is, the easier it is to place in InDesign.
Open a new Word doc. Copy and paste all of what’s in the old doc into the new Word doc. Delete the very last paragraph mark from the new Word doc. This is an old trick editors use to fix misbehaving or corrupt Word files.
In Word Options, turn off all autocorrect functions except ‘Flag repeated words’ and Replace straight quotes with smart quotes.’
Examine the styles in the new Word doc. Ensure that every element is styled in the way you want it. If you don’t know what that means, study this: https://shaunakelly.com/word/styles/stylesms.html
One drastic way to apply styles from scratch in Word is to remove all formatting first. To do that, open the Styles palette. Select everything. Click “clear all” at the top of the palette. Again, you’re better off styling each element individually than letting Word automatically style or format anything.
If messing with Word is too daunting, remove all formatting from the Word doc, place it in InDesign and style each element there.