I'm making a game for the first time and I need help.

I'm making a game adaptation of my short novel using RPG Maker VX Ace.
I'm doing well so far, but how can I make it so an event can only activate

after going into a certain house?

The plan is Joe (the protagonist) goes into his house and finds that his children

are dead, he picks up his sword and heads out.

I've made an event to encounter the town pest the night stalker but I only want the

sprite to show after he has gone into his house and come out again.

How can I do this?

Make a switch trigger on the transfer event that makes him go into his house, then use that switch as a condition for the thoe stalker guy.

Could you explain in more detail please? I'm really new

I think you should play the variables guide and then look at it in the editor.
The focus of the game are variables, but to show those it also needed to use switches and sequences, and you can look up there how they are done.


Follow the link in my signature, the variable guide is linked from there - and the other tutorials and tips there will probably help as well.

I recommend YouTube tutorials for what you're looking for.. and yes it is Triggers that you're going to need. It's pretty basic stuff once you get your head around it, you'll be fine. (Love the Ian Crying Avatar ;) Nice one. So yeah... I can make this into more detail if you like.

Do you have any YouTube videos you know that have helped you in the past?

Not really... not to a degree where I feel like I've learnt something... It's just covering basics and making a start on how to use "Events" sufficiently. 

http://forums.rpgmakerweb.com/index.php?/topic/28939-a-list-of-rmvx-ace-tutorials/

Follow this link to see the full list of tutorials available for RPG Maker. These are your friend. Love them, cherish them, appreciate them, absorb them...and so on, and so forth. :D