Given the criteria you set forward, it appears that you are looking for a home defense and occasional target shooting.
Given that criteria a revolver would be my first pick. You need to select one which fits your hand and has good point ability. In other words when you pick it up the sites naturally align.
For me the Ruger double actions do not point properly and are uncomfortable to shoot. Depending on the grips S&Ws generally fit the bill. That is a decision you will have to make by visiting a shop and range and trying them out. Try every model in stock.
The issue between single action or double action is the next question. I tend toward double action because the single action requires a separate action to fire. Double actions you pull the trigger and everything happens. DAs are harder to shoot accurately than a single action. Cowboy guns are fun.
Barrel length. Given your 25 yd requirement I would go with a 4 inch tube. It is more difficult to conceal is accurate. I own a Dan Wesson with 4 barrels. I use the 4 in barrel for carry and the 8 in for hunting. I don't care for the 2.5" and the 6". Once again that is something you must decide.
Caliber I would recommend 38/357. 38 spl ammo is relative cheap and available. 357 mag is more expensive but is available.
For a first pistol I would recommend a quality revolver in 357 mag with a four inch barrel.