Yes—if your photos are blurry in low light, raising ISO is usually the right move. In practice, noise is often much less objectionable than motion blur or camera shake. Don’t intentionally underexpose to avoid noise; that generally doesn’t help.

With the 18-55mm kit lens, you’re already limited by its relatively small maximum aperture, so your main options are:

• use the widest aperture available
• raise ISO as needed
• avoid shutter speeds so slow that subject movement or hand shake causes blur
• add flash if possible

For indoor parties, a flash is one of the biggest improvements you can make. An external flash is especially useful, and bouncing it off the ceiling can give softer light and help reduce red-eye.

If you eventually buy another lens, a cheap 50mm f/1.8 or f/1.4 is a classic low-light option. Its much wider aperture lets in far more light than the kit lens, which can mean faster shutter speeds and cleaner images. Just keep in mind that wider apertures also give shallower depth of field.