An SPD cleat is a cycling shoe with a two bolt clip system that allows you to clip to your bike pedal and deliver more power to the pedals with your foot.
The biggest problem with SPD clips is that you can’t walk on them. Because they are optimized for endurance and distance cycling, it is assumed that the wearer will be changing into their cleats to ride a long distance and then out of their cleats at the end of the trail.
For that reason, SPD clips probably aren’t the greatest for someone who has a short commute or who is riding deliveries. The on and off in the cleats would be tiring at best, and make your job much more difficult.
But if you want to commute say, 10 or 15 miles to and from school or work, the added advantage of the energy efficiency is worth throwing a second pair of shoes into your backpack and changing when you arrive.
For that scenario, you may want to consider a SPD compatible sandal for attaching your cleats too. The reason being that they can be an all season shoe for you when coupled with socks (Not noticeable in a black sandal with black socks) for cool weather, the sandal by itself for hot days, and a waterproof cover with insulated socks for cold weather.
It is ideal, of course, to have a pair of closed shoes for winter and a pair of cycling sandals for summer, but if you have to choose just one, then I would go with the option that meets your climate.
If you’re only likely to need waterproof boot covers and socks for a few select days of the year and live somewhere where the thought of wearing shoes and socks for daily commute is suffocating, I will go with a sandal. This will make you more likely to get that bike out, even on the hottest days of summer.
Conversely, if you live in a climate with a lot of rain and cool weather, I wouldn’t bother with the sandal. The couple of times a year that you would wish for the circulation for your feet wouldn’t be worth the trouble of always having to round up all the appropriate layers to make your footwear useful.