Ropes – Rock climbing ropes come in a few different varieties that are designed for specific scenarios. Most gym, toprope, or sport climbers will want a dynamic rope of moderate diameter to add durability. Ropes come in single, double, and twin; dynamic, semi-static, and static; dry and wet; and numerous other varieties.
Harnesses – Harnesses also come in many varieties, but a modern sport climbing harness will work for almost any climbing scenario. If you get into more specialized types of climbing like big wall or alpine climbing, you’ll want a more specific harness, but a sport harness will do. Just be sure you know how to use it properly.
Helmets – Rock climbing helmets are pretty easy to get right as long as you get one that’s UIAA certified. Find one that’s comfortable and fits you well and you’ll be fine. You can get a ultralight helmet later when you decide to take on bigger objectives. 
​Carabiners – Any outdoor climber is going to need at least a handfull of carabiners, both locking and non-locking. Any well-known brand makes good, reliable carabiners. Just be sure not to get any carabiner not specifically designed for climbing. Hardware store biners won’t do the job.
Belay Devices – Belay devices come in a few styles. Tube style devices are the most common and are versatile enough to be used just about anywhere. An assisted braking device such as a Grigri can be the next step up from a tube style device, but I recommend not getting an assisted braking device until you’re comfortable with the tubular device. 
 Protection – Rock climbing protection comes in a variety of styles and types, but the general idea is that protection is a way for you to secure your rope, yourself, and the climbing system to the wall. Nuts, cams, and hexes are most commonly used, but many specialized pro can be purchased for various applications. Don’t worry about purchasing protection until you’ve figured out the basics. It’s expensive and most useful by someone who knows principles of anchor building and rope dynamics.
Shoes – Rock climbing shoes are essential to anyone wanting to climb seriously and will improve your climbing abilities instantly. Pick a comfortable but snug shoe. You don’t want extra space in the toe box. For your first pair of climbing shoes, get one that’s not too aggressive and it will be more comfortable to wear all day at the gym or the crag.
Belay Gloves – Belay gloves are totally optional but make it much easier to belay or rappel without getting rope burn or getting your hands all dirty from the rope. Pick a pair designed for belaying and they’ll have a hole to clip a biner to, but any pair of leather gloves will work.
Chalk and Chalk Bags – Chalk is optional as well, but can be very helpful if you tend to get sweaty hands when you work out or when you get nervous. You’ll be doing both when rock climbing. The chalk improves your grip on the rock. You don’t need much but having it can make the difference between topping out and lowering early.
Slings – Slings are useful for connecting all kinds of things while climbing and you should get a few 120 cm (double length) slings to have handy when you need to extend a draw or an anchor.
Prusiks & Accessory Cord – Prusiks are loops of accessory cord set up for quick use in rappelling or other scenarios where you need a “third hand” to hold the rope tight i n case you lose control or need to lock off. Accessory cord is a 6 or 7 mm diameter nylon cord that’s useful for all kinds of things, but mostly you’ll use it as an anchor material to build quad anchors, cordolette anchors, or other rigs.
Webbing – Webbing is useful for building ground anchors, safety anchors on a toprope route, or other anchors. I like to carry at least 50 feet of webbing with me so I have many anchor options at the top of a cliff.