...and if you're Austria, try to make an alliance (or informal NAPs, if multiplayer), because the odds are pretty decent that somebody's already planning to make you a target. Similar goes for Prussia -- nice army, but if France DoW's and Russia and Austria opportunistically join in, you've got some problems.
UK is probably first or second easiest for a newbie from the POV of survival -- so long as you control the Channel with Nelson and your fleet, and preferably blockade the French fleets ASAP, the French corps shouldn't be walking over. There's also decent diplomatic prospects with Sweden. Achieving domination instead of survival isn't as simple, but at least you're not likely to die fast, even against human players.
One of the smaller, more limited scenarios might have been good to include -- 1812 Campaign, for instance, might teach about foraging and supply, while letting diplomacy be a minor aspect. :D :D