Your budget you set for each YouTube ad can be edited at anytime.  I suggest starting on the lower end to make sure it's converting and then increasing it.

I recommend selecting all the 3 networks to promote your YouTube ad

When creating a YouTube ad you can narrow it down to show in a certain country, state or even city.  This is what I love about YouTube ads is how targeted you can get. 

Depending on your target demographic you may want to select another language other then english which is the default. 

Device targeting is very important because remember people can't click on an add when watching a YouTube video on their mobile device.  At least not yet.  So you may want to target your videos to only desktop and laptops. 

Scheduling a start date for your campaign and a end date can be important especially if you have a limited budget.  Otherwise the campaign can go on and on spending money until you stop it.  Also you can schedule at time of day and which days you want the ads to run which is powerful.  This is because if you know that your targeted audience only is on during specific hours why bother showing it at other times.

 A view occurs when a viewer watches 30 seconds of your video (or the duration if the video is shorter than 30 seconds) or interacts with your video, whichever comes first. Video interactions include clicks on the call-to-action overlays (CTAs), cards, and companion banners.  If they skip your add before the 30 seconds is up then you don't pay the full amount of the bid.

This is a video ad I spent some money on to promote that didn't convert very well.  I took too long to get to the content and so people just skipped it.