if you take the Metro (modern, but i hope you like crowds!) to the Red Fort, you will probably get off at Chandni Chowk and walk (or get a cycle rickshaw, as you will likely be approached by so many) through Chandni Chowk to get to the Lahore Gate.
the main street (Chandni Chowk Road) is full of people, scooters, rickshaws, and assorted vehicles (including animal-drawn) going every which way, but step off of the main drag to the side streets and you’ll find yourself on alternately crowded or relatively empty alleyways, crammed with shops and strings of electricity cables stretching like spiderwebs overhead. it’s really really overwhelming, especially to me who only got four and a half hours of sleep the night before. the constant honking, construction sounds, rickshaw drivers trying to get you as their customer, people and vehicles barely paying attention to you and nearly mowing you over.
it’s a very fine line between exciting vibrancy and sensory overload. if you ever feel overwhelmed, there’s a calm McDonald’s on the left side of the road (if you’re facing the Fort), or even better, go down some side streets and wander into the quieter alleyways for a calmer glimpse into local life.
remember to keep an eye on your belongings — these tight quarters are ripe for pickpocketing! and it’d be good if you had maps available offline on your phone (or online, if you have data service) so you don’t get lost in the side streets.
and here’s a bonus from Jama Masjid, the largest mosque in India — to get there you’ll have to traverse Chandni Chowk as well. (TIL the hard way it’s closed for a couple hours midday to non-Muslims — i was there around 12:45 and had to return at 2:00. this was not a scam. what is a scam, and one i fell for, was having an unofficial guide show me around — i ended up paying him 250 rupees at the end basically for walking with me around the site. if someone takes your ticket and walks in with you, say no and get it back! just go by yourself — you can walk pretty much anywhere.)
well, heck, here’s a pano of the mosque’s main square: