How to install fire detectors?

[Kir2]

I have relocated from my parents' house, and now I live alone. Honestly, I am not an experienced person in such questions as paying the bills and house security. There is no fire detector in my place. I want to ask if anyone knows how to install it? Are there any companies that can do it for me? I have seen several DIY products, but I do not want to waste time on it. Maybe Ajax security systems are quite good ones? Have you heard anything about them?

[dfelsent]

Smoke detectors are easily available at hardware stores and Lowe’s and Home Depot and hardware stores and maybe lots of other stores among other places. There are codes for where you want them. Top of the stairs and so on.
Easy to diy.
Search for “smoke detector locations.”
And don’t forget about a CO (carbon monoxide) detector.
And replace the batteries every spring and fall to avoid that annoying chirp.

Not hard, and worth the effort.