Hello community this is my first post. I have tried to add all the possible details.
Currently we have business basic licenses (no power automate per user or per flow or capacity-add on license) and I am the one responsible to Drive adoption for power automate.
We are not using any power apps.
I have created around 8 to 10 flows with the individual users account itself and adding myself as an additional owner. So all the flows are using under those individual users account.
The flows include 2 to 3 approvals based on SharePoint file creation, looking for a row in excel online based on specific keywords in the subject of an email, saving emails with specific keywords to SharePoint etc. nothing complicated.
I have checked Microsoft documentation and found that every user in 365 plan get 2000 monthly API calls for free. Flows typically runs 8-10 times in a day so this shouldn’t be a bottleneck. I was thinking that the free plan should be more than enough for our needs.
Honestly I found the power automate admin Center just before few days and encountered that I am exceeding file storage capacity.
I opened a case with Microsoft support but they informed me to free up the file storage capacity using dynamics 365 portal. For me it did not show any data so Microsoft support executive informed me that the admin centre is showing incorrect data.
I am still worried because admin center throws a message: "You are exceeding the files today is capacity certain environments can be affected"
capacity usage details are provided below.

Following are my questions:
1) How Do i know which files are taking up the 855.14 MB? can I delete those without impacting the actual sharepoint files?
2) How do I forecast the storage capacity?
3) checked the capacity add-on on Microsoft 365 product page, but it mentions to add only 10k API calls. How about the file storage?
I have checked Microsoft documentation and Power Automate licensing document but it is still not clear.
Requesting help from the experts to understand all the details about the capacity in Power Automate.