How to upload a picture onto form?

I believe that you would like to add a photo onto the form itself so that it is shown to everyone viewing the form.

If that is, you can do it by adding Image tool to your form from Form Tools.

It will then allow you to add the photo from various sources to your form.

The Enter URL option will allow you to simply add a link to the photo that you own and have uploaded somewhere and it will grab it for you.

The Upload Image File option allows you to add any image from your computer.

Choose From Existing Images option allows you to simply pick the image from your own images if you have uploaded it previously (even if done so on some other form).

Security Certificate Seal is an easy way to show the security seal image on your forms by just selecting the same option.