I honestly don’t wanna have a instructor I just wanna be able to sing so, can I learn to sing by just playing acoustic guitar ?
Have you ever seen people who are amazing guitarists but when they start singing they don’t sound so good? It is uncommon though not impossible to learn to sing by playing guitar. Most people will advise you to take lessons because if not, you could develop bad habits and could end up damaging your voice and not even know it.
You could just get books on singing. They come with audio CD’s so you can hear how the vocal exercises sound. They are the alternative to getting lessons with an actual teacher. You can learn at your own pace, its great. Some people even learn better this way. It can be a bit frustrating at times because maybe you won’t fully understand something but you can always Google it.
I suggest "Singing for Dummies" and "The Complete Idiot’s Guide to Singing", they are both very good books and easy to follow along with because they don’t require any knowledge to music. They teach the traditional way of singing and come with tons of vocal theory which is very important to know too.