Hi nwcleaningllc,
There are two different ways you can generate a web-to-lead form from within Method, you can either choose the "Basic" or "Advanced" setup. I only bring this up because if you were to go with the default options from the Basic setup, this Contact information does get carried over to the Opportunity that gets created.
If you used the Basic setup and want to edit this form, or you have any advanced form, you would find this Opportunity information in Steps 3of9 and 8of9 of the Web-To-Lead setup. Step 3of9 is where you choose which Opportunity fields you want to include receive values for. Step 8of9 is where you can go to view all the fields/tables being used in your WebForm, and you can choose how each field gets populated from here. For the case of the Opportunity fields, by default they are being populated from the Contact Information the user enters in the first few lines of the webform.
My suggestion to you would be to either use the Basic webform, then make whatever adjustments you want from there, mostly because the Opportunity fields should already be setup to get populated with inputed values. You could also create an Advanced Webform, however you will have to manually enter your details for the Opportunity step.
Hope this helps,
-Ben