Are you a resident or non-resident of Illinois? Either way, you will just need a regular hunting license and habitat stamp.
Second, yes you can use the mini-14, but I would use ballistic tip ammo for they don't skip like the heavier ammo does from the .223 for the houses are so close is why they won't let us use HP rifles to hunt deer with.
Third, no you don't need tags for 'yotes, just plenty of ammo and a place to go!!!! What part of Il are you plannning to hunt?