It is a big commitment - you need shoes and pedals, two of each.
If you buy new pedals, there will be some cleats that come with them. If you buy used pedals, there's no guarantee cleats will be included.
There are two main styles - the 3 bolt road design with a plastic cleat shaped like a triangle. These poke down below the shoe and make walking a bit clacky.
Everything else tends to be metal cleats and much smaller, with two bolt designs and often recessed into a sole. These are termed "MTB cleats"
And there are also less common designs like Eggbeaters etc.
You need shoes that fit closely around the foot, but provide room in the toebox for your shape of foot.
Also consider some shoes are warmer than others, with some designed for summer ventilation and others for water shedding warmth.
As for technique - you need to ride and establish a muscle memory for unclipping.
Some pedals let you set a low release tension, which makes getting out easier.
Riding quiet roads can help you work on the new skill - I found that riding in traffic required more focus, and I could slip back into old habits at first.
If you will only ride the bike and not walk, then road cleats might work best. Look KEO or shimano SPD-SL would be ideal and readily-available. If you are likely to walk around a lot off the bike, then recessed MTB cleats will save you shoe changes or the risk of sliding/falling over at the cost of some small efficiency loss.
The one-and-only time I have fallen off due to cleats was when doing a very low-speed turn with a tight radius, AND I overbalanced AND the inside foot didn't unclip quick enough. That was only embarassing, my horizontal speed was basically nothing.
I was lucky enough to start with used shoes, despite being too small they proved useful. Trying to go back to flat pedals after a few months felt quite "disconnected" from the road bike. I even put road pedals on my MTB, so not to need another pair of shoes.
Cleats are expensive for what they are. Plastic 3 bolt road ones last around 6 months for me. Original LOOK ones are $35-$50 NZ retail locally, so I've been buying plastic ones from aliexpress for $8-12 a pair and they work well enough.
Very few if any places will offer a trial - your best bet is to see if anyone you know has spare shoes to test with.