Hi @Rohit Waghela , welcome to Q&A forum!
For your questions:
1.What is the file size upload limit for SharePoint online?
Currently the File upload limit for SharePoint Online in Office 365 Business Essentials and Office 365 Business Premium is 250 GB per file.
2. Is there any way to change file size to allow me to upload a file?
You can't change these settings in SharePoint online.You can change the file size upload limit in an on-premises environment, but it's not possible in SharePoint Online because it's a shared setting for all the tenants.
A similar post for your reference:
What is the file size upload limit for SharePoint online
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