Help with model train setup

Recently I saw a short video clip of a model train set that was perched on top of kitchen cabinets.  It ran in the kitchen is an "L" shaped track. The train was a trolley and it went back and forth---not a loop track.

I know nothing about model trains. I had a  plastic circle track as a kid that lasted maybe the month of December that about it.

Can I put together a track like what I described above on the cheap? Apx 10 feet in length. Something that just goes back and forth?

Ill try to link in the video clip here: https://www.facebook.com/reel/646851100994890?fs=e&s=TIeQ9V&mibextid=0NULKw

Look up automatic reversers

Lionel had a No.50 Gang car. with bumpers that would switch the polarity on contact. You could probably do something like that on the cheap.

If you are set on a trolley, Lionel also made a No.60 Trolley. It's a more expensive than a gang car.

I am only familiar with G-Scale. It's the biggest of the common scales, also called Garden Scale. To me it is just a lot more fun and also better for kids. They can be pricey, but keep an eye on used deals and it isn't too bad. Right now is not the right time to buy - everyone wants one for around the tree. 
 

So, for g scale, LGB makes an auto reverser for this purpose. LGB 10345. 

This guy shows how it works pretty well. The kit only comes with one bump-stop, but the second one he has is for looks only.

Facebook find close-ish to you. You'd still need the reverser, and presumably straight track, but this is a decent but not great deal on a starter set. Not a trolley though. 

Bachmann has a complete trolley set in HO scale. It's about $150.

Bachmann's EZ-track is generally pretty good. 

The trolley set in the scale of your choice is going to be the easy answer. I picked up a module kit for one of my Lionel trains that uses sensors to stop and reverse it which is pretty nice but I forget the maker. It reverses the train at each end and lets you program station stops along the way.