If this is your first tank, I would consider using these three as “indicator species” and focus on maintaining water quality and thus, the health of these easy corals.
To answer your question, these corals won’t sting enough to kill corals and in fact, they’re relatively peaceful and popularly used to make what is known as a “Zoanthid garden” as they (zoanthids) can live together while touching.
You might even find some stores or reefers selling rocks containing all three at times (Xenia, GSP, and Zoanthids) touching each other.
As you progress your journey into this wonderful hobby, you might find your wallet feeling rather light and your desire to acquire and successfully grow colorful, rare corals so i would just place these three species together or separate in your tank (on the rocks or on the sand bed) and see how they do for the first few months before investing into LPS (large polyp stony) or SPS (small polyp stony) corals as you’ll want to organize space with these aforementioned corals as some grow quickly and others pack a terrible punch/sting and will need ample distance from other corals.
Good practices like making space around corals to allow future growth and preventing stinging warfare, regular water changes, and water quality stability are key in this hobby.
Just make sure to cycle your tank with bacteria before adding livestock, use distilled or RODI water when mixing saltwater, and always do research to avoid making expensive mistakes!
Some corals might be $10 and others might be $600+ so just be mindful and enjoy
