Can a website know that

All the pictures are taken using one phone?
and from one places?
is there any way to edit that data?

Most GPS enabled devices saves location-based data with each image

Websites can indeed see your image data, especially if you are uploading .jpg files which contain exif data. You can use some tools online to check the exif data of the image you are planning to upload and edit or delete it

They are data that can be easily extracted from the metadata of the photos.

I do not think there is a definitive way to detect what you are asking. I mean you could take the gps coordinates if available.. and also take the file creation time (or if the date is available as exif data) or something... but that will only work if the coordinates are available; as well as if you could approximate (e.g. draw a bigger circle on the map and see if the points lie within the circle) the co ordinates properly... but only if the gps coordinates are there. Otherwise, I don't see a way from the pixel values itself.

As for the checking which device took the pictures, I am not sure. It does not hurt to see what are in the exif and try to figure it out.

google exif editor, exif purge, or similar phrases and you will find some tools to get you there.

Following

This "hidden data" (not hidden at all actually) is called "metadata". As depolad mention, you can search for exif editor, but if you want to be totally sure, you can save these images on a computer without any of your data, open the image and screenshot them to save again. The new files will not share any metadata of old files.