Unfortunately... the info you have isn't enough to say without just guessing. That info should be ( but isn't from what little I've read ) provided by either the model manufacturer as recommended battery and prop sizes or by the motor manufacturer as a recommended range of battery and/or prop sizes.
As purely a guess in the ranges... perhaps between 2-3 cell lipo battery... but I'd have to give a wider range of props... between 9-11" ... don't take those as facts, they are just guesses.
Motor sizes aren't really standardized.... usually when given like the one you mentioned... the 4023 is either the size of the outside can at 40mm around and 23mm deep... or it's the size of the internal stator. Typically I think most use the outer can size since it's more useful so you can judge if it'll fit within the area you plan to use it in. The later number is how many thousand ( k is short for kilo ) rotations it makes per volt .
How many volts or amps the motor is less obvious since it can't be determined by size... it has to do with how it's wound and what gauge wire is used.
So what I'd suggest.... first start with the right info since you aren't being given it straight up. You need to know the exact model name and do internet searches on the exact model and version if there are more than one. Then read any info you can find... I'd probably focus on forums ( such as this ) and check some advertisements also ( I doubt if they didn't list it where you are getting it from, other sites won't either but it can't hurt ). Now repeat the process with the exact make/model of motor and see if the info you find can be verified.
Many ( if not most ) toy grade models are like this... slim to no technical information. Quality kits and/or builds will almost always give you the info you are now having to look for.