There aren't any stupid questions. You're learning something new and it's good to research and ask than to jump in and possibly waste supplies.
I use approximately 1 T honey ppo; although sometimes it may be a little less. (Tip: put a little oil from the batch on the spoon so the honey doesn't stick to it.) I'm a little paranoid when I add sugar, honey or syrup. I remove enough of the water which I will use for the lye , warm it and then dissolve the sugary goodness in it. Then I'll add this into the batch either before or after I add the lye mixture. I'm not
that persnickety when it comes to adding honey or whatever.
This is only what I do. Other people do it differently so you'll want to pick which tip works best for you.
Also, honey can heat up a loaf so you'll want to keep an eye on it if you're using a FO that gets hot.
As for coffee grounds, I save the grounds from a pot of coffee, spread them on a plate, let dry and then grind. Again, it's just what I do. It's not the only way. I'd try the grounds from the cafe just to see if you like them in your soap. Some people don't like them. If you do, then I'd keep getting them from the cafe as long as they were willing to give them. Free is good. It helps to reduce your cost for the soap. You could take some soap to them after it's cured as a 'thank you' gift for their generosity. You might even try simmering the grounds in water to see if you can get more coffee out of them for the liquid. I don't know if it will work but it's worth trying once.
Just a suggestion but you may want to go lightly on the grounds since they can be scratchy. I wasn't told this when I made my first soap with coffee grounds and I about screamed when I tried to use it. Yes, sadly I am a wuss. I don't know what amount to recommend but maybe just try a tablespoon or two ppo for the first time. You can always add more for the next batch if you don't think it's enough.
I haven't used coffee as the liquid but only because I prefer to drink it. I keep saying one of these days but then...