To post a picture you hit 'post reply' and then underneath the text box there is a 'Manage Attachments' box. From here you can select a picture to upload
I'm afraid the store has given you the wrong information regarding supplementation. He needs a calcium powder without d3 for every feeding along with a calcium with d3 (like you already have) to be used only once every two weeks and a multivitamin powder to be used once every two weeks. I'm not familiar with the Flukers brand but this is a very common mistake that stores make. Overdosing on vitamin D3 can lead to metabolic bone disease and the early death of your cham. It's something that you should try to sort as soon as possible. Since they got this wrong it's likely they told you other things that are incorrect. I would suggest filling out this form
https://www.chameleonforums.com/how-ask-help-66/ and posting another picture of your setup so we can make suggestions to ensure your cham gets the best care he can.
Carrots are a great start for your feeders but variety is best, the nutrients you give your feeders will be passed on to your chameleon, meaning more variety will lead to a healthier and happier cham. Here's some information on gutloading
https://www.chameleonforums.com/blogs/sandrachameleon/75-feeder-nutrition-gutloading.html and a care sheet
https://www.chameleonforums.com/care/caresheets/veiled/