Ok for starters - the words mechanical, mods, and beginners don't go hand in hand. But, if you've got prior experience with vaping, you accepted responsibility for your safety and the safety of those around you, and you got a pretty good grasp on battery safety, ohm's law, resistance, volts, currents (amps), and power (watts) - then lets gets started:
For a mechanical - yes - Smok Magneto is a good start - usually between $35-$50 based on where you get it. Features a magnetic switch, telescopic tube (to fit multiple batteries) and I've seen them come in brass and stainless. Pretty low maintenance until the magnets give - so if you're going with a Magneto - pick up some rare-earth magnets - granted maybe a bit on the pricey side - but it beats replacing the magnets in the switch every so many weeks.
Atomizer - For flavor - pick up something like a Trident clone or even a Kayfun clone. Again - $25-$50. Both are pretty good - the Kayfun - (Rebuildable Tank Atomizer) RTA, the Trident - (Rebuildable Dripping Atomizer) RDA - Both produce sick flavor. I prefer the Kayfun over the Trident just because it's a tank. And because I had issues with the Trident screws. So good luck. As far as clouds - MutationX or Doge. I prefer the Doge just because of the adjustability of it and in my opinion, better flavor as well.
Batteries - well bud - I can ONLY suggest TWO (2) BATTERY MANUFACTURERS HERE: PANASONIC OR SONY. AND ANY PANASONIC OR SONY BATTERY THAT HAS AN UNPROTECTED 30 AMP LIMIT OR HIGHER FROM THESE 2 MANUFACTURERS ONLY! SEE BATTERY SAFETY IF YOU AREN'T 1000% CERTAIN OF WHAT YOU'RE GETTING YOURSELF INTO! Wait, WHAT?! Unprotected?!? Unfortunately - protected batteries ARE in fact safer, however they do NOT perform well in the vaping scenario. So, be sure to look at Sony VTC4's, VTC5's and some of the Panasonic batteries for safety purposes.
And that's all I can come up with. We all start somewhere, and as hard as it is for me to start here, I figured I'd do my spiel first - answer questions later. Good luck - vape on (or VOOP if that's your thing) - and be safe. CW - Out.