Are there any World War I group tours?

I googled and this website came up & their tours look very interesting: The Cultural Experience (WWI-the Western front. )
I also see Get Your Guide offers a day tour to the Somme from Paris. There were several more results to my query.

In Bruges, Quasimodo Tours offers a day trip, Flanders Field, with an option to attend the Last Post Ceremony in Ypres.

A self-driving tour is great for flexibility, but if you want that 'mini-bus' middle ground, look for day departures out of Ypres or Amiens. There are several local outfits that run small group vans to the main Somme or Flanders fields for a reasonable daily rate.

I did two one-day Viator WW I minivan tours in 2018 from Paris (Somme and Verdun) and one to from Brussels (Flanders). The French produced a "Great War Map" for the Centennial but I haven't searched for my copy on the bookcases lately so I don't have an exact reference. Googling Western Front maps suggests many sources. Verdun is a long drive east of Paris, but that is the area the US Army was located for its Meuse-Argonne Offensive in 1918 and the major US Military Cemetery is there. . From Paris north to Brussels the route goes along much of the front line on the Somme (there is a great museum in Perrone; the Australian Memorial in Villers-Bretonneux just east of Amiens marks the location where the ANZAC Corps stopped the German 1918 offensive) and then to Flanders (and the Last Post Ceremony at the Menim Gate in Ypres.

There are several companies who do Battlefield Tours. We did a small day tour (8 of us) to the Somme (from Paris) with Blue Fox tours which included Villers Bretonneux, last year. The driver/guide took us to various areas of note, including the Sir John Monash Centre at Villers Bretonneux. Although the tour was not geared towards Americans (there were two on the trip), I believe the first battle US troops fought on the Western Front was under the command Monash, who was the first Commander to be knighted on the battlefield 300 years. I found the day trip very emotional as we were able to visit the graves of two great Uncles who were killed on the Somme

I did the Quasimodo tour out of Bruges last Fall. It was outstanding.

My in-laws did a WWI tour in 2018 which was tweaked to include participants' special interests (for instance, my MIL, who is an amateur historian, was interested in the fates of young men from her rural village - she supplied some basic information and the guide did the rest). It started and ended in Lille, and went into Belgium and Northern France. I don't have a name but I think you would find it by including Lille in your Google search.

Lavandula

I think everyone should see Ypres. The dead in the three battles there almost equal the total number of the US Civil War. Its' current beautiful bucolic feel is such a striking contrast to what happened there. And in cemeteries in England, you can see gravestones that say "killed at Ypres".