Welcome to the forum.
Selling your trains depends upon what items you have, their condition, and the demand for what you have. Clean the items before you photograph them. Looking at various auctions is a good thing to educate yourself with the prices of items in various conditions. If there are any hobby shops in your area, see if they are interested in your items. The same with any local train clubs. See if there are any upcoming train shows near your area also. This forum has a classified section that you can easily post the numbers of the items you have, to give an idea of what you have. You may find that you may have to sell individual items, rather than the whole lot as one.

Larry