I have 3 questions, feel free to answer one, two, three or none

1)
I have a utility that I need to run in the background and it needs to be started at boot.

Right now I have to login as a user, and run it (and keep that user logged in so they keep running it). I know there must be a better solution, I would like to hear it

2)
In addition, I wish to have fetchmail run at bootup. I can figure out how to configure and run it... even in daemon mode, but I'm not sure how to make it start automatically at boot time, and how to tell it to use my configuration.

3)
I have a number of services running I wish only to be accessible to one other machine on my network. I know there are default files for this, but I've found redhat 8 often doesn't use these "normal" files. Can someone provide a brief explanation on how to do this?

Thanks for the help, I realize that these questions can probably be answered by reading through man pages and such, but I find (being new to linux) that the man pages use vocabulary I'm not used to

THANKS!
Greg

Could someone please tell me where I COULD find this information?

Which distro are you using? Redhat 8?

1) Google rc.local and /etc/rc.*
2) Same as 1)
3) Some firewall/packet filtering setup?

for 1 and 2, just add the relevant commands to /etc/rc.local and you'll be golden.