It's worth having the tools (cheap of the internet) so you can strip and clean + greese the components. Trying to clean grit from the sprocket cluster or around the BB is near impossible without taking them off.
+1
Do the simple adjustments yourself using online guides. Then consider getting a basic starter tool set and after about 6 months, strip the bike (probably don't need to bother with headset if it's cartridge bearing) and rebuild with assembly compound on all threads, on seatpost, adjust and grease wheel bearings etc.
Whilst it might sound like I'm taking the mick, I'm not. New bikes are assembled completely dry, and cheaper hubs have poor quality seals and need more regular greasing/servicing - I know a few people with bikes that had to be completely overhauled after just 12-18 months, including paying for a stuck bottom bracket to be removed and replacement hubs, for this exact reason.
If that's all too much of a ball ache and you're happy taking it to a shop - make sure you take it somewhere reliable though with a good workshop trade - then follow something like this:
1st service (6-8 weeks) - just ask for a rudimentary check and adjust of gears/brakes. Should be very cheap
Full service (annually, preferably in early spring/late winter) - ask for hubs to be stripped, greased and re-assembled (or just a chick on bearings if sealed), get the crankset and bottom bracket removed for threads to be greased and reassembled, all new cables, new cassette & chain if required (likely), strip/grease/reassemble headset, grease seatpost, check tyres/brake pads/rims etc. for wear. This is going to cost ~£100+ and maybe more if parts need replacing. This is when a £60 lifeline tool kit and a selection of grease/lube starts looking like good value if you have the time free.
In between just make sure to keep drivetrain clean and well lubed and check over all moving parts for wear and tear. Oh and enjoy riding your well cared for machine