This might be a stupid question, I'm just starting out, but I didn't find any clear instructions on the subject so far.
How are offerings supposed to be given? Like: 'eat it yourself and dedicate it to the deity'; 'pour it on the ground outside as a tribute'; leave it on the altar until it spoils then throw it out'; ... ?
In my case I was thinking a milk/yogurt offering for Brighid, who seems willing to help but not to be my main patron (so long as directing a question at her and seeing if I get the chills in answer is a valid way to tell these kinds of things?), and I live in a house with two cats and a dog...
Would the cats eating the offering count as a proxy, or as a failed offering? (Of course if having the cats eat it is a valid path, I would take the time to ferment the milk into yogurt, I'm not looking to make my little princesses sick.)
First and foremost - There is no such thing as a stupid question. There are only questions, and asking them is how we learn. So you keep on asking and NEVER be ashamed to do it. An inquisitive mind and a desire to learn will serve you well in any life. 💜
As for offerings, it really depends on what it is you want to offer. Some shrines will leave a food offering out for the length of a ritual or church service or a day, depending on perishability, and then distribute it to the clergy or congregation to eat, or donate it to the local community. (I can recall a number of Sundays when times were rough that the pastor quietly slipped my mother other half of the loaf they'd cut up for communion bread. As I understand it now, this is something that lots of churches do.)
For home offerings, I tend to choose things that I can either reuse for the household or use to feed my neighbors or the local wildlife. Both of these are things that honor Brighid's aspects as a caretaker of animals and a provider of charity. My go-to's are usually dry oatmeal, milk, and honey (or a drop of honey in a shotglass of milk). The oatmeal becomes breakfast or bread and the milk and honey get mixed in.
In the case of the situation you describe, I'd put out a little cup of milk as an offering when you mean to ask your question and sit for a while in quiet contemplation. Give your thoughts time to settle, think on your question and the possible answers, and see if you feel a little spark or a nudge in a particular direction. Sometimes the answer won't come right away while you're sitting there, but letting it marinate can help your mind untangle things a bit. The nudge might come later.
Since you have the concern of pets drinking the milk, I'd suggest drinking it yourself once the period of contemplation is done. When you set it out, you can say or think something that indicates it's an offering, something shared, something given with respect and gratitude. When you drink it, you can lift it in a toast and say or think something along the lines of, "Thank you for your guidance."
I've done this in ritual settings before, with milk or whiskey, and it seems to work well. Brighid has been firm but patient in my experience with her and personally, I feel like she appreciates that desire to learn. Of course, all of this is my personal experience and your mileage will certainly vary. I think that as long as you come with a spirit of sincerity and respect, you'll be all right.
(And yes, definitely keep the critters away from the offerings if it's something they shouldn't be eating. If it's pet-safe and you want them to share in the snacking afterward, go for it. Brighid loves animals, after all.)