When I run an A/B test experiment on the first step in the funnel, how does the A/B test affect the reporting of the goal and funnel? Are both redirect URLs from the experiment tracked as the first step in the funnel?

Assuming your A/B Test experiment defines variations using “Redirects” feature, then pageviews are tracked on the “Redirect URL” of each variation. Therefore in your Funnel step, you must use the “URL Matches the expression” and write for example “page1.htm|page2.htm” meaning the funnel step will be activated when user views either page1.htm or page2.htm

However if your experiment defines variations using JavaScript in one page URL, then all users viewing any variation will be normally tracked as pageview on this page URL. So the funnel step will be activated if it matches that page URL.