Is it possible to add customer input ids to individual fields?

I use a system similar to Hubspot, but no Gravity Forms plugin exists for it. I currently host forms from my system on my website, but they are difficult to style and I get bombarded with spam from them. I purchased Gravity Forms for another company I used to work for, but I want to make sure it will work for my purposed now. However, in order to have it tie into the system I use, I need to be able to add an input id to certain form fields in Gravity Forms. Is this possible and how would I go about doing so? Are there HTML files associated with each form that I can easily edit?