At 8 weeks a pup is going to have to go 6 or 8 or more times a day. First thing in the morning (and I do mean first thing), last thing at night, every time it eats or drinks, immediately after every nap. Might also get a sudden urge to go is playing excitedly.
Take the puppy out and stand with it where you want it to go. Do not play with it or give any real attention. When it starts to sniff or circle, tell it to pee or poo (or whatever you want to use as your command). When it pees or poos, say "good boy/girl". Quite soon you will be able to initiate the sequence by telling it to poo or pee.
If you see the pup peeing or pooing in the house or making the sniffing/circling preparations to do so, immediately say "No - outside", grab the pup and take it outside. You do not have time to find your shoes, so keep some slip-ons near the door.
If the pup has already peed or pooed, don't tell it off. If you do, it will associate your unhappiness not with the fact that it has peed or pooed, but with the pee or poo itself - the pup only knows what is happening now and not what happened two minutes ago. This might well lead the pup to try to hide the poo, picking it up in its mouth and dropping it elsewhere - or, worse still, to eat it. Either way, don't let the little bugger kiss you until its cleaned its teeth. Again, just scoop the puppy up and take him outside - there is a chance that you interrupted the pee/poo and there is still more to come.
You might also want to put paper down near an outside door and train him/her that the paper is an OK place to go in an emergency. If you see the pup making preparations and there is not enough time to get outside (perhaps you are not dressed)), get him/her to the paper and go through the good boy/girl routine when he/she performs.
You're going to have to be with the pup constantly for at least 6 weeks or more while it gets full control. If there are short (and I mean very short) periods when the pup is going to have to be on its own, you should confine it to as small a place as possible. In the US they would cage a pup at such times, but I think confining it to a kitchen or other room with a vinyl floor-covering is sufficient.
Best of luck!