As long as has_more is set to true there is more data available. You can get this data by increasing the page parameter in your request subsequently and running new request with that changed page parameter.
The next url for your example would then be
https://api.stackexchange.com/docs/users#page=2&pagesize=100&order=desc&sort=reputation&filter=default&site=stackoverflow&run=true
The other both properties quota_remaining and quota_max refer to the maximum amount of queries you may issue on that day to the API. In your example case you have used 46 request on that day and may do another 9954.
WRT to the later comments
You can add filters to your request in order to have some more fields shown or left out in the response. In the adhoc query form you used, you can access these filters on the top right of the respective form.
There just select edit and search for total in the section .wrapper. Afterwards click save. Afterwards it should show a filter id like !-q2Rj6nE, which is appended to your queries.
However as the FAQ states here, the total field is a rather expensive function and should be avoided to use on a regular basis, when you retrieve items anyway.