AR Parts recommendations

I’m about to buy a PSA AR-15 that basically comes with nothing but the rifle and the mag, no irons, nothing else. I’m looking for recommendations for the following parts.

• Flip up/back up Iron sights
• A primary sight/scope (preferably with some magnification but I’m a novice so if it’s not recommended I’ll live without)
• Sling
• Weapon light

I’d like to be of the buy once cry once mindset but obviously im on a budget since im buying from PSA, so best bang for your buck options you got would be appreciated.

Thanks comrades