First off DO NOT feed lions or any other saltwater predator guppies or goldfish. You will cause major liver problems and early death. Freshwater feeders are too fatty and nutrient deficient. Get grass shrimp and get it weened onto frozen sea foods ASAP. Damsels are a healthy snack too
Your damsel will probably be lunch in the near future no matter what species of lion it is, the clown might be able to hold its own and get big enough not to be dinner.
What species of lion is it? For any of the Pterois genus that 46 gallon you have listed will get very small very fast as a Volitans can get to its full 15" size in less than 18 months(and that is in captivity) and anything less than a 100gal is going to be too small for it to turn around in. If one of the dwarf species you might be ok. If one of the bigger species you would be wise to bring it back and exchange for a smaller lion species unless by saying you are getting a bigger tank soon you mean in the next few months.
As for tankmates, anything small enough to fit or fast enough to be caught is dinner and lions have disproportionately sized mouths for their lengths. Big lions like Vols will even eat smaller dwarf lions, spines do not matter. In your case of a 46 with the bio-load that a lion puts out any more fish really are not an option since anything else will have to be bigger than a lion and even the dwarves get decently sized. Eels do well with lions and eat the same food for the most part. Stay away from triggerfish and puffers.
On the bright side they will not harm your corals
