The amount of physical stamina, not to mention mental toughness, required to grind out a long Farmer's Walk will produce great results. You will stimulate gains in your lower back and traps. Your grip strength will be tested, as well as your cardio conditioning, the further you travel. However, your biceps and/or pecs will NOT get pumped. You will not get "jacked" ( I still don't know-or care- what "jacked" really means.)
The Farmer's Walk is an excellent "finisher" after a tough workout. You can also make it a workout in and of itself. It's not difficult to master, you don't need a coach to instruct you on the finer points of the movement. You simply bend down, grasp the weights, deadlift them, and then start walking. You just need some sort of implements to carry, and a place to carry them. If you have a parking lot or a sidewalk at your gym, that would work fine. If you train at home, a backyard, sidewalk, or long driveway would do the trick. Another option would be to drive to a school or park and utilize a track or open area. There are numerous ways of getting it done, and your options are limited only by your imagination. There is one proviso that I would like to point out: You will probably get some strange looks from passersby, particularly if you do these in a park or residential neighborhood. However, once you make up your mind to do it, you won't even notice. Or care.
As far as the "implements" you'll be carrying, there are many options from which to choose. If you have access to heavy dumbbells, then that will work just fine. Just be careful about dropping them when you're fatigued. And you WILL get fatigued. You can also use a Trap Bar or Hex Bar. It's not the best option in my opinion, as you will find yourself trying to keep the bar balanced as your moving. Also, if you are very large, you might not fit properly inside a Trap Bar. I remember watching Drew Israel trying to use one years ago. Drew is one of the largest-and most powerful-men I've ever met. His arms would chafe against his thighs because he was literally too big for a standard Trap Bar. Of course he solved this problem by purchasing a custom-made Trap Bar that weighed about 100 Lbs., but that's another story.
Because of the popularity of the Farmer's Walk, today there are numerous special implements that are available. I first purchased a pair from Drew about twenty years ago, and I still have them, and use them. They weigh 70 kg each, and have a loading area to add olympic plates. The first time I ever tried a Farmer's Walk was at Dr. Ken's Iron Island Gym. Several of us would go outside, behind the gym in back of the building. Dr. Ken had some nice "toys" in the back. Several large ( 500 Lb. and up) tires for flipping, a length of large nautical chain, steel I-Beams, and several water-filled kegs provided plenty of "fun" for anybody willing to challenge themselves.
The back of the gym was perfect for doing a Farmer's Walk because there was plenty of space to walk. You could walk a set distance, turn around and go back. You would repeat as often as you could. This brings me to another hint: If you are carrying your weights in a straight path, i.e. no turn around, make sure you don't go too far. In other words, if you carry your implements to the point of failure, then you will faced with the problem of getting them back. I always preferred to walk a distance of about 50'-100' and then turn around. The turning around part can be tricky. You will have to slow down a bit in order to do it, otherwise your momentum can cause you slip.
I would also recommend that you make sure that you are thoroughly warmed up before doing this movement. Do not do it cold. A strained calf or hamstring will not only prevent you from doing justice to your workout, but it could set back your training. One time we were training in back of the gym, and we were attempting to carry 250 Lbs. in each hand. We set the distance at 100'. I was able to carry the weights the full distance, but on the return trip I felt something in my left calf. It initially felt as if someone had hit me with a pebble or rock, but I had actually incurred a strain to my calf muscle. End of workout. The moral of the story is that your muscles should be warm, and thoroughly stretched, before attempting something you've never tried before.
If you've never tried the Farmer's Walk, give it a try. There is nothing quite like fighting your way through a set distance. When your lower back is screaming, your forearms burning, and you feel as if you're about to collapse from exhaustion, you get to see just how mentally tough you really are. And, of course, upon completion of your workout, you will feel the satisfaction of having worked hard. And of having strengthened your entire body.