Discus can be kept with other fish but you need to be careful when selecting tank mates.
Discus tend to be very peacful..that said they are still Cichlids and can be nasty at times , tho usually with in their species.
they are often paired with peaceful tetras, cardinals are the norm, bu can be kept with other tetras.
I have mine with bn's
if you keep them you will need to keep in mind they do best in a group of atleast 5 and you need to be mindful of the 10-15 gal per discus rule.
if you aquire young discus, they are best kept in a bare bottom tank with frequent water changes, young discus should be fed 4-6 X daily and uneaten food removed = water changes.