Need Help Setting Up an NVR Security System + Suggestions for Buying Parts

[OneTapHero]

Hi everyone,I’m planning to set up an budget friendly NVR-based security system for my home and need some advice. I don't have a concrete idea about the components I need or where to buy them at reasonable prices.
Here’s my plan:

• Installing at least 4 cameras (2 outdoors) to cover entry points, outdoor spaces, and the main hall, with plans to upgrade later.
• I want a HDD that can store 14 days of footage.
• Not sure what camera specs (resolution, FoV, etc.) or features (night vision, AI detection) I should prioritize.
• I don’t know any reliable sources for quality parts at fair prices. Local retailers in my city quote absurdly high prices and often overcharge.

Questions I have:

1. Which NVR brands/models are beginner-friendly yet reliable?
2. What features should I look for in cameras?
3. How do I calculate storage capacity for 4-6 cameras running 24/7?
4. Any tips on cable management and camera placement?
5. Where can I buy these components at fair prices? Any trusted online stores or retailers in Tamil Nadu (or nearby)?

If you’ve set up an NVR system before, please share your recommendations or experiences. Links to helpful guides are also welcome!