Well… it’s certainly possible to solo mine in null sec, not exactly recommended. If you’re an Alpha that can only fly a Venture, talk to your corp and get in on a moon mining fleet. Even in a Venture a couple hours slurping up moon goo should give you a decent infusion of money when you sell it (especially if you’re a newbro). After that you will eventually want to get a better mining ship. However even if you’re not moon mining, you’re much better off in a fleet. It’s safer then being alone if enemies come along, if a porpoise or orca is providing boosts you collect ore faster, and also it’s more fun and social to chat with your fleetmates.
If you’re really set on solo-mining for some reason and you can only fly a venture, equip some gas miners on it, probe down a wormhole and start ninja-huffing. It pays pretty good, can be exciting, and pays better then what you get from your usual asteroid.