The Schluchtensteig has its own hiking sign, a diamond with a blue S (water), a red triangle (mountain) and a green crescent (nature). The Schluchtensteig crosses other hiking trails with similar signs (e.g. the Albsteig), so you have to look carefully to follow the right sign.
There are signposted parking spaces in Stühlingen near the town hall. You can leave your car here for the whole week.
If you want to return to Stühlingen from your destination in Wehr by public transport, take the SBG bus 7335 to Brennet/Kreis Waldshut railway station, then take the RB 30 to Lauchringen, and from there take the SBG bus 7338 to the Catholic church in Stühlingen. The total journey time is approximately 1.5 hours.