Welcome to the forum, and congratulations on your recent acquisition!

To help you we need a few things from you:
First a list of all the numbers you find on your rolling stock and accessories.
Secondly, some nice pictures of the rolling stock, track and accessories.

If they are Lionel, then they are '0' gauge.

To start, clean everything including the wheels, roller pickups on the locos, and the track with a rag dipped in Naphtha.

Get a set of Labelle train lubricants and lightly oil all axle bearings and lightly grease all gears.
https://labelle-lubricants.com/shop/106-107-combo-pak-food-safe/

Chances are the cord on any transformer you may have is in need of replacement.

These are just the basics to get your trains up and running. Any pictures you post may help identify any other parts or work that may be needed.

Let us know how you are doing, and ask questions if needed.


Larry