Hi Shaunny7 -
As Arno noted, those trips are all discounted. if you see fares listed in the Timetable that I linked you to, they are typically the half-fare. Most Swiss have a form of half-fare discount card, and that cost number is for their benefit ( and yours.)
You will need to purchase a ticket for each journey, which will cost half the normal fare. If a conductor asks to see your ticket, you will show both the pass and the ticket.
Tickets may be bought at many convenient machines. There will be choice of ticket type indicated at one point or another during the process. It will show an indication for "1/2" or for "children" . That is what you select.
The machines operate in English, German, French and Italian.
You can also buy at ticket counters in manned stations. You will have no problem with English if you do not speak German.
When buying a ticket in a city, you may buy at a ticket counter in a station or at a ticket machine at a tram or bus stop, or also in the stations. . The machines offer a bewildering array of options.
I have found a "24 hour ticket" to be the simplest to use in cities, and it costs only approximately as much as 2-3 single tickets. It does what it says. It is good for 24 hours from the time of purchase within the "Zone" or zones ( described below).
In addition to single ticket ( typically good for 2 hours on any bus or train or tram within the "Zone" shown on the ticket), there are options to cover more than one zone (extra cost) sometimes a so-called "9 o'clock ticket" - good after the 9 AM rush hour until - I believe - midnight, as well as (often) a "short trip ticket good for 1/2 hour and somewhat cheaper than the single fare ticket. There is usually a zone map on the machine or nearby.
Downtown Zürich (or any city) is "Zone 110." Zürich airport is in zone 121. Wettingen is outside the Zürich Verkehrs Verein (ZVV, Zürich traffic association) zones to the northwest. You should be able to get the best Zürich 24 hour card at Wettingen, but I'm not sure what it would be. You probably should ask at the station; possibly your colleagues at work in Wettingen can help you. You will need to know whether you will plan to outside the city center.
In addition to ticket machines and manned ticket counters, the traffic association for both Luzern and Zürich have a manned office in the lower levels of the stations. They will sell you a ticket and provide advice on what to buy. They have route maps and small booklets listing the schedules and stops.
Much of this material is now available on Smartphones, but I don't know how much. That will gradually replace some printed materials.
On buses and trams in the cities, you will not show your ticket and half fare card ("Halb-tax" or "Halb-Abo") unless a special ticket inspector boards the car and asks for tickets. If you do not have one, you are fined on the spot. Make sure that you have a ticket.