Hi Darren, what size is the fish tank?
Your immediate (pre-fish tank) shopping list should include the following:
* dechlorinator that deals with ammonia and nitrite
* liquid test kit for ammonia and nitrite (usually it's cheaper to get a set that contains nitrate and pH as well, and GH and KG is also useful) - test strips are not worth your money are they are not accurate enough
* airline (read about
importance of acclimatisation and
how to do it - click the links!)
* (alcohol) thermometer
For transporting the fish, you will need:
* fish bags or buckets with lids (fill 1/3 tank water, 2/3 air)
* polystyrene or chiller/cooler box (without the thing that makes them cold) to keep the fish warm
* nets to catch the fish
* bucket/hose for lugging water about
* bucket for substrate if the tank is large
* bucket for plant/other decor
* 2 strong people for moving the tank if it is large or any 2 people if it is over 2 ft long
Fish bags and poly box should be available from your LFS (local fish store/shop); if you plan to use fish bags, as them to show you how to use them.
The most important point about transporting fish is to make sure that the filter remains wet and does not come into contacts with tap water that has not been dechlorinated. Read about the nitrogen cycle for further details.
So, start by unplugging all equipment, then bag the fish, then remove all decor, then remove all equipment (make sure filter stays wet by placing in a fish bag, bucket or at the very least into a few carrier bags without holes), then drain all the water, remove substrate, carry the tank to car (it needs to sit on something that is flat).
Once you get home, add substrate back, dechlorinate new water by the bucketful or add enough dechlorinator for all the water and fill the tank half way up, add decor, add heater (make sure it is submerged completely, unless instructions say otherwise), plug in heater, top up the tank, make sure it is at the right temperature (use kettle or hot tap to get it right, I prefer to use kettle in older houses), add the filter into the tank and switch on,
acclimatise fish (very important, or the change in water hardness can kill them), move the fish over to the new tank, top up as needed, leave the lights off for the first day and do not feed in the first day.
After the first day, the lights should be on a timer and you should start by feeding no more than they can eat in 30-60 seconds, once per day, with no food on one day per week (increasing to twice per day in the long run).
What species are the snails? Are they ramshorns? Physa spp.? Snails are usually a sign of a larger problem (again, could be part of the reason that you're getting it for free), so I recommend that you ignore them throughout the move (or remove some of them), and then just look after the tank well. Snail eating fish are a bad idea because most grow quite large or are aggressive, or can even cause other problems with the tank.
What fish are already in the fish tank? Most likely, given that it is going for free, they're either too big for the tank, not compatible and/or the numbers per species are bad.