1) Welcome to the Party!
2) As you are obviously new here, I have some suggestions to help us all help you:
When you post, please post your entire configuration including (but not limited to) your installation method (7.X.X?) and vicidial version with build (VERSION: 2.X-XXXx ... BUILD: #####-####).
This IS a requirement for posting along with reading the stickies (at the top of each forum) and the manager's manual (available on EFLO.net, both free and paid versions)
You should also post: Asterisk version, telephony hardware (model number is helpful here), cluster information if you have one, and whether any other software is installed in the box. If your installation method is "manual/from scratch" you must post your operating system with version (and the .iso version from which you installed your original operating system) plus a link to the installation instructions you used. If your installation is "Hosted" list the site name of the host.
If this is a "Cloud" or "Virtual" server, please note the technology involved along with the version of that techology (ie: VMware Server Version 2.0.2). If it is not, merely stating the Motherboard model # and CPU would be helpful.
Similar to This:
Vicibox X.X from .iso | Vicidial X.X.X-XXX Build XXXXXX-XXXX | Asterisk X.X.X | Single Server | No Digium/Sangoma Hardware | No Extra Software After Installation | Intel DG35EC | Core2Quad Q6600
3) Of course you can merely increase the Auto Dial Level, but then you may have other factors that interfere such as max trunks in the dialer and max trunks from your carrier. Try it. See if 5 or 6 is better. But ...
4) This is not a magic pill moment. You should understand that every setting in the Campaign and System Settings and Admin->Servers is all about getting agents on the phone with prospects. They all have some sort of effect and each situation is different. So: Read The Vicidial Manager's Manual. Front to back. Don't skip anything. Go over every setting in the Campaign Detail view and click on the help buttons. Probably best to make a copy of the campaign before you make any changes to this one, so you can revert to the original settings after you compare results from any changes.
5) If AMD is on, turn it off (this is controlled by the Campaign Routing Extension in Campaign Detail view). Note that turning this off will likely cause less people to hang up immediately after answering (4 seconds of dead air pisses off the general public, and that's the basic result of using a program to listen to the front of the call and decide if it's an answering machine or a human: dead air!).