Hi Melissa,
The fields that you are looking for must be available in the correct table. If you take a look in the Field List in the Report Designer, you can see which tables the report is based off of. In my example below, the report is based off the Estimate and EstimateLine table. If you expand these options, you will see the different fields available in the table to place on the report. You can also take a look at your tables in your Method account by going to Customize>Tables/Fields.
I recommend a few webinars that might help you learn a little more about how to design reports in the Report Designer. If you take a look at our Webinars page, and scroll down near the bottom of the page, you'll find the Report Designer section. We also have an article in our Help Center with a few more tutorial videos available here. I hope this helps, but if you have additional questions, or would like to expand on your post, feel free to reply here!
Jason