I am a guitar player and a vocalist. I want to record my acoustic guitar and singing with a microphone. Now that I have bought myself an inexpensive condenser microphone (Neewer NW-1500), I got to know that I'll have to use audio interface or some kind of phantom power while I use it with my laptop. I wanna know if the mixers or the audio interfaces only could do the work (without phantom power) or will I have to buy all of them (audio interface and the phantom power)?
You can do this with only an interface because many interfaces include phantom power. Usually phantom power is included with interfaces and mixers. Very rarely do people buy a separate phantom power supply.
When you buy an interface, just make sure it also has phantom power. Most interfaces do.
The Neewer NW-1500 appears to be provided with a 3.5mm TRS jack plug, which suggests it is designed for direct connection to a computer's Mic socket providing 'plug in power' (which is not 'phantom powering' as usually understood). However, although the online documentation is sketchy, it seems possible that if the supplied cable is replaced with a standard XLR to XLR 'microphone cable' it will work with the 48v phantom power supplied by the XLR mic socket on most 'audio interfaces'.
This seems to be a very cheap item, more concerned with what it looks like than how it performs! But sure, give it a try. If the supplied cable into your computer's Mic socket works, you're good to go.