Yes. Everything is possible. But let me be very honest and realistic with you, starting an online store isn't an easy job. You cannot handle it all alone. First of all, you've to decide your audience/market, whether the store is exclusively for Pakistan or for international market. And then you've to decide what you're going to sell - you can choose to sell all computer hardware or few reserved components like GPUs, CPUs and MOBOs.
You then need a functional e-commerce site (like
www.Czone.com.pk) where you can display your products, rates and users can navigate/order directly from the store. You have to purchase a
DOMAIN NAME like
www.Example.com and you need a good web hosting service. I personally recommend
www.HosterPK.com as they're reliable and affordable.
If you're not a technical person then you can hire someone who can take care of your website. And it's not easy to get visitors on your site. Either you need a marketing strategy and advertising fund or you gotta hire an SEO so that your store appears in Google. I'm pretty sure you'll be discouraged/disappointed by reading my reply but this message isn't intended for such purposes, just giving you a realistic outlook.
I can go much deep explaining everything from customer support to payment processing but the things which you will figure out yourself from your experience will be the best. Good luck, brother!