To turn in your bounties, it's best to turn them in at the same system where you killed the pirate. If you do that, you'll get full credit for the kills. Other systems won't be able to accept the bounties at all, unless you go to a station with an Interstellar Factors. He's kind of a 'bounty broker' if you will. He'll buy all of your bounties, but will charge you a 25% fee for cashing them in. It's a real time saver if you don't want to fly around to where you got the bounties.
There are a few websites that will tell you where the nearest I.F. is located, but since you're already using Inara, here's a link to that page:https://inara.cz/galaxy-nearest/
Just enter your current system name, hit Search, then click on Interstellar Factions. It'll show you the closest stations.
Regarding mining, it is super profitable and worth some time to get the hang of. Deep core mining isn't the big draw that it used to be. Painite, low temp diamonds, and maybe 1-2 other surface materials is where it's at these days. Here's some info shamelessly copied from a friend of mine that he posted a few months back....
Where to mine, find overlapping hotspots and where to sell:http://edtools.ddns.net/miner
"How to do it:
find an overlapping hotspot location with the mining link above.
Go to that location and use your surface scanner to find the overlapping hotspots. Fly towards them and slow down. Don't drop with one selected. I think you will drop at the center of the selected one. Drop midway between them with nothing selected. Run away from anybody that shows up if you have any goodies. If you only have only limpets just let them scan you.
Set up your firegroups with your lasers and collectors on one button. This way you always have your max limpets out. Set your secondary button as your prospectors. I also left on a few abrasion blasters on another fire group since some rocks will have painite surface deposits.
Look for triangle shaped rocks and prospect them. The guide I read said that any rock over 30% is worth your time. I fire 1 prospector and look for another target in the same general direction then fire another. If you do it right you will save time over using one prospector. Once I find a good one I get close to minimize collector flying time. With 6 lasers I overheat. I fire till the level of materials gets down to 50% then cool for a few seconds before I finish it off. You could use less lasers since it doesn't really matter as long as you stay ahead of the limpets. While I'm waiting for limpets I select the next target for my prospector and fire it off. Don't forget to set your limpets to ignore everything but painite and mats."
I hope that helps.