Please follow the below instructions to do changes in checkout form:
1. From your Shopify admin, go to Settings > Checkout.
2. In the Form options section, make the appropriate changes.
3. Click Save.
If helpful then please Like and Accept Solution. Do you need custom changes on store ? Hire us. Feel free to Contact me for shopify help on email@example.com Shopify Design Changes | Shopify Custom Theme Design and Development | Shopify App Development