Welcome to the Forum, I have to say that on first view the Loco looked to be 32. But looking again the Track certainly look slike it is Peco so as it is a bit finer Rail than LGB or others it can be a bit deceaving. There are quite a few Start Uo Lines this Year on the Forum. Navigatibg through can be a bit tricky till you get to understand the Forum. Callum is a newish starter and his threads will probably give you some ideas:-
https://www.gscalecentral.net/threa...oject-update-12-august-september-2016.307931/
That link was a little vid of his recent extension.
Another who started his line recently was Henri
https://www.gscalecentral.net/threads/rabbit-hill-tramways.307258/
Both these will give you some idea's that should help the beginner.
Another on You Tube is Zac. Just search for "How not to build a Garden Railway"
His Vids are hilarious and give some good tips. But some are a bit shall we say doubtful. Still if you review his stuff you can see what works and what did not!
Re your Track,mnot sure what space you have, but inevitably you will need some Points and Curves. Peco can be curved but can be devilish tricky to get Even Curves with it. I have a couple of Templates that I use. However if you are happy to take Tight Curves then Peco do Setrack ones, these for the beginner will give you a Guaranteed Curve admittedly tight Radius but equivalent to the Sharpest LGB ones at around 600mm Radius.
Good luck with your efforts and do not be afraid to ask more as you get going. Oh plus lots of pictures as well!
JonD