The choices seem to have a budget limit of $500 or so. As an only gun, the M&P would be first. 9mm will do the job, as there is plenty of inexpensive ammo to shoot for familiarity, and serious loads for defensive carry.
For a long arm, still keeping in mind budget and all around use, a lever action in .30-30. Again, ammo is inexpensive, widely available. That allows some more range use, and using iron sights tightens up the skill level. The lever is a good choice for a HD gun, short enough to use indoors, carries enough ammo for the actual number of rounds fired in encounters, and has enough range for outdoor use on the property. As America's #1 hunting rifle and caliber for the last hundred years, it's more than proven it's ability. It's also light and handy to carry in the field with adequate power for most of the ranges hunters see.
It's not modern or tacticool, even despised as a bit Joe Fudd, and that is exactly it's advantage. It's not a weapon of mass destruction in the eyes of the ignorant. Don't pay for new, clean used ones are frequently on the market. The money saved can buy ammo.
The alternate choice in a long arm would be a Bargain Bin AR15 from CMMG. Many would write extensively on why it's not a high quality military grade end of the world firearm. Most on the list aren't, either. The CMMG gets an assembled AR as a starter to learn the use of a military carbine, offers all the utility of the lever and more, is equally handy and easy to use. The recoil in 5.56 is even lighter than the .30-30, has good ballistics for everything except some conservation departments requirement for deer hunting. As more money becomes available, familiarity with it will give some insight into what improvements you might add, such as a red dot optic. Ammo is inexpensive and easy to buy.
Ruger and S&W also make AR's, some have reported discounting into the $500 range lately. The production build up after the presidential election is meeting the economic downturn in cash flow, and the savvy consumer will be looking for bargains whatever they choose to buy.
