Retrofit lockout for a suspension fork? I am new for cycling. I am searching for bikes on which I will ride mostly on roads, but also on terrains/mountains occasionally. After doing a few researches online, I finally decided to buy a hybrid bike.

Mostly people are suggesting to buy a Hybrid Bike which doesn't have suspension and disc brakes (even I'm not worried about disc brakes). So I thought to buy a bike which has a suspension fork with lockout.

My question is, is it instead also possible to get a lockout mechanism from store to add to a suspension fork which doesn't have a lockout itself?
You shouldn't count on it, no. Low-end and touring forks may not have the parts available at all. With medium-to-high end MTB forks, the parts may be available but it often requires exchanging most of the innards, making it a much too costly proposition. It in not just a matter of adding a lever to the top.