If the information on this site is correct for your drive (you should check this is right), it should be fine. That page states the max power consumption as 1.535W - well under the upper limit of ~4W available from the USB port of the Pi. It’s only an issue for high performance SSDs that can sometimes require nearly 10W.
You can see the nominal and typical power requirements of a Pi 4 here:
Note that while the Pi can supply 1.2A max from its USB ports, in practise this is not practical to achieve. Keeping the limit for a single device down to about 0.8A (hence the 4W) still leaves enough headroom for things like your keyboard and mouse.
Honestly, the official Pi Supply is over specced. You would need to have every single port and GPIO pin maxxed out, and the processor going full tilt to get near that 3A limit.
For what you’re doing it should be more than enough, and have plenty of headroom left to spare. Sounds like the first bottleneck that you would hit is the current the Pi can provide via USB, and even that is a long way off (You SSD max of 1.5W @ 5V is only 1.5 / 5 = 0.3A).
Check out this video + article Graham did up when the Pi 4 was first released, he maxxed it out at 1.12 Amps:
And this stress testing article is also handy:
Long story short, from what you’ve said, you’re perfectly safe with the offical supply. Time to start digging into setup guides so you can hit the ground running when your gear arrives