Step 1: So you want to whoop. I think, the easiest— and in my opinion, the best— way to start is to get a toy quadcopter (quad) as the platform on which to build on.
The toy drone I recommend is the Eachine E011. It’s inexpensive that you’re not out too much if you decide the hobby is not for you. Its motors are powerful enough that you don’t need to upgrade it immediately. And most importantly, by simply adding parts, it provides a continuous upgrade path. Get one, get lots of spare lithium-polymer (LiPo) batteries, and fly as much as you can by line-of-sight (LOS). This simply means keeping your quad in sight while flying it.
Step 2: When you can fly well by LOS and you’ve decided to see what first person view (FPV) flying and whooping is all about, it’s time to get your FPV gear.
You need an FPV camera. The camera I recommend is a lightweight all-in-one (AIO) camera such as the Turbowing Cyclops. It is similar in form and function to the popular CM275T camera but dispenses of the button for flipping the picture. This results in a slightly lighter weight.
You also need a video receiver. The least expensive way, is to get an OTG receiver which connects to an Android phone/tablet and use it as a monitor. The primary concern with OTG receivers is the latency. I do all my FPV flying using OTG receiver and, honestly, I don’t have problems. The latency difference between OTG receivers and FPV goggles only becomes an issue at high speeds and maneuvers. Otherwise, it’s probably not a problem for most fliers.
However, if you have the budget, my recommendation would be to get FPV goggles. If you find that the hobby is for you, you’re getting one eventually. If not, you can always sell it.
Step 3: When you can fly well in FPV with angle mode, it’s time to get a hobby-grade flight controller (FC) with acro mode. ba
The combination I recommend is the Eachine Beecore Flysky AFHDS 2A FC coupled with the Flysky i6 TX. The Flysky i6 is a basic transmitter but it has 6 channels and can store multiple models. Many would recommend Frsky but the cost of entry is a bit steeper.
Step 4: When you can fly well in FPV with acro mode, it’s time to unleash the beast in your Tiny Whoop.
This is a MAJOR evolution. You will need to replace nearly everything: the motors, the FC, and the frame. In their place you’re getting brushless (BL) motors, FC, electronic speed controllers (ESC), a receiver (RX), and a frame. It’s going to be EXPENSIVE. But you’re committed to this (or perhaps hooked already), right? Right?
The frame I recommend is the Rakonheli 66mm brushless whoop frame. It is only very slightly larger than the standard 65mm whoop. And you get to keep your canopy and camera. For the motors I recommend Racerstar BR0703 15000KV motors. Not too fast that you drain your batteries too fast and not too slow that you wonder why you ever went brushless. For the FC I recommend the Teeny1S F4 FC. For the ESC I recommend the Teeny1s 4-in-1 6A ESC. They’re both available as a package. For the RX, I recommend the Flysky RX2A Pro micro RX.