I am trying to get from wengen to vernazza Italy. Can someone please tell me which website to go to book a train? I am having a hard time finding one!

There are lots of train booking sites in Europe, and all those I've seen have pages in English.

Basically, you're going to have to get to Milan, where you can get a local train to Varenna. You can use the Swiss railway site to research the trip, or to buy tickets.

https://www.sbb.ch/en/timetable.html

The closest station to Wengen that has a direct train to Milan is Spiez, but you'd have to take two different trains to get to Spiez. In addition to the few direct train, which leaves Spiez at 14:05, there are also routings that have a change of train somewhere. If you don't mind getting to Varenna in the late afternoon, you might prefer to get the direct train from Spiez to Milan, to save yourself changing trains at least once more.

Once you're in Milan, you can get a local TrenNord train to Varenna-Esino. The station is in Varenna. You can see the timetables for this train on the Trenitalia web site:

http://www.trenitalia.com/tcom-en

The whole trip is on local trains, except for the part on the EC train from Spiez (or Brig) to Milan. These local trains have no reservations, so there's no advantage for buying the tickets online. The EC train has reserved seats, and offers excellent discounts if you purchase well in advance (at least one week, better two weeks).

The whole journey will take you over 6 hours, and you'll have to take a minimum of five different trains, six if you don't choose the direct train from Spiez. I hope you're planning to travel light!

The closest station to Wengen that has a direct train to Milan is Spiez, but you'd have to take two different trains to get to Spiez.>

Acdtually three trains to get to Spiez - Wengen to Lauterbrunnen; change there for Interlaken-Ost and then there for Spiez and then there for trains to Italy.

Bvlenci has given all the relevant info as usual.

For lots of info on Swiss and Italian trains in general check www.seat61.com -great info on discounted tickets for trains; www.budgeteuropetravel.com and www.ricksteves.com.

Wengen (insignificant small Swiss village) - Vernazza (insignificant tiny Italian village): timetable

Wengen dp 7.03 - Vernazza ar 15.15, change at Lauterbrunnen, Interlaken Ost, Spiez, Brig, Milano C, Levanto.

Wengen dp 12.33 - Vernazza ar 20.33, change at Lauterbrunnen, Interlaken Ost, Spiez, Milano C, Genova PP, La Spezia.

Wengen dp 13.03 - Vernazza ar 21.23, change at Lauterbrunnen, Interlaken Ost, Spiez, Brig, Milano C, Sestri Levante.

Standard tickets can be bought at any somewhat important Swiss railway station counter.

Web tickets:
Wengen - Spiez, Brig or Milan: www.sbb.ch
Spiez, Brig or Milan - Vernazza: www.trenitalia.it

bvlenci has given info for Milano to Varenna-Esino, so disregard the part after "Once you're in Milan..."

Milan to Vernazza involves a change at either Levanto or La Spezia. (You could also go via Genoa, but it takes longer and involves another connection.) This part of your journey will take 3+ hours, so if you're doing Wengen to Vernazza in one day, you're looking at probably 8 hours on trains.

There should be no need to make so many changes of train between Milan and Vernazza. There are hourly (at least) direct trains from Milano Centrale to Varenna-Esino, and the trip takes about an hour. These trains are operated by Trenord, not Trenitalia, but you can buy their tickets from Trenitalia. Maybe the website that Necker used doesn't show Trenord trains. You can see them on the Trenitalia website, whose link I gave above.

Vernazza is on the Italian Riviera.

Varenna is on Lago di Como.

The OP wants to from Switzerland to the Italian Riviera. It is impossible to take a Trenord train to the Italian Riviera.

neckervd has given the right schedule - Vernazza in Cinque Terre - bvlenci is an Italian expert just understandably got Vernazza mixed up by stupid mistake. Always otherwise gives splendid right on advice!

Sorry, I momentarily confused the two places. It's worse than I thought.

But even Milan to Vernazza can be done all by regional trains though quicker ones run the route too -but the beauty of regional trains is that you just show up buy ticket and take any of them -no pre-booking hassles - there are not even any reserved seats possible I think.