If I connect the current speakers to the receiver- will there be room to connect another set as well?
Most likely. Most receiver s offer some sort of speaker selection on the front panel.
Check (the receiver and./or the manual} for a Speaker A/B switch, or some similar terminology.
Also , do the inputs mean that I can connect the turntable and a CD player to the receiver?
Yes. The CD player can should be connected to one of the "stereo audio" inputs.
As for that turntable, if you use the "phono" input on the receiver, switch the turntable's internal preamp off. If you cant. then use another of the "stereo audio" inputs.
The reason is that a real phono input (which your receiver seems to have) expects a very low level signal from a phonograph cartridge (needle?) and require extra amplification and some special equalization.
Older receivers offered this a a matter of course. Due to the fact that turntables have pretty much gone the way of the Edsel and the original VW bug, most (not all) new receivers don't bother to go through the expense of including this additional stage of amplification.