Bikes do pick up a little crud as they're ridden, so keep the moving bits clean.
From now on, keep old toothbrushes and any t-shirts or shirts you're about to throw away. You need a lot of rags to keep a bike clean.
Most parts of a bike needs no looking after, but do keep a casual eye on cables, brakes, gearchange mechs and the driveline.
Tyres lose pressure, so buy yourself a track pump (doesn't have to be a super-posh one) and get into the habit of keeping an eye on pressures. You may be surprised how much they can lose in 7-10 days. A track pump will be one of the best things you buy.
When you lube the chain, wipe off any excess. I tend to lube in the evening and wipe the chain clean in the morning - but that's just faddism on my part.
Generally, keep an eye on things. Quick-release skewers... spokes... cables...
Make sure that what needs to be tight is tight (seat post et al).
But... there's no need to be clambering all over your bike with a spanner or an Allen Key every day or so.
Most of all... enjoy the bike.