You really don't need much in the way of upgrades for what you describe, the chassis is a solid piece that will get you running and respond predictably to tuning changes. If you feel like spending some money on the car the most useful 'upgrades' early on are tuning pieces like springs, swaybars, a faster servo, that sort of thing.

Shock oil in touring car is typically between 30 and 50 weight, with 35-40 being most common in that range. Losi or TLR shock oil is pretty good and as its silicone (all shock oil is these days) it wont degrade with time. I prefer it to Associated oil because its dyed and you can see what kind of oil you had in the shock before, in case I forgot. I forget things like that.

The kit tires are a long-wearing hard rubber and are perfectly good for running around in the street but will be much less grippy than the softer Rally Blocks.