Looks like you are in Sandbox mode, so you will not get any public data, you will only get data from you or your sandbox users.
Try search for an hashtag that you have posted a photo for, then you will just see that photo in API response.
Once you get approved with public_content permission, and go live, you will see all data.
max_tag_id and min_tag_id are encrypted now, you cannot just generate, you first make a API call without the max_id or min_id, you will get the response with 20 results with max_tag_id in the pagination section of API response, which you can use this max_tag_id to make next API call, for next set of 20 results.
(and btw you will have pagination in API response only if you are approved by Instagram and are out of Sandbox, so go figure, good luck)
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solved Pathetic state of Instagram API