Whats the first thing I should do?

[dbv6s]

Can’t see the original pictures but what’s wrong with the current interior? dropping a few £k on a custom interior wouldn’t have been my first choice

You mentioned buying a nice wax... get the car ceramic coated for a few hundred quid, much better option.
Look into tyre upgrades - a lot on here prefer the Michelin Pilot sport 4S’s
You could liven up the interior by changing the console trims - genuine or dipped carbon fibre

Not sure if your into performance mods but plenty out there - have a look at DAvid Appleby website

[Tel]

Think the first thing I did was topped up the tank and went out for hours and hours to get the 'running - in' bit done as quickly as!

Ceramic or what have you depends on whether you intend keeping the car or flogging it on after a few years.
It's a superficial coating that offers no protection from everyday driving, however it's a little more 'shiney' than the clear coat, and the crud washes off a little easier.

[MM1963]

Thanks. I can never take that Clear Coat seriously after watching 'Fargo'..'oh but that clear coat' I'll live with the interior for a bit first, but after seeing those beautiful seats, it's hard to resist.
Tyres will have to stay until I wear them out, as they have new ones at present.
And yes Monday is reserved for scaring the bejeebers out of myself no doubt and getting to know what it corners like, as I'm a bit of a corner freak after writing an E55 Mercedes off, a few years ago..I split the sump, proper job as they say down SW. But I got back in and learnt, on the peddle not off lol.
Appreciate the comments guys/gals...

[steviegtr]

What is the actual model you are getting.

[MM1963]

2017 (MY18?) V6 R-Dynamic 20" Gyros, Red, Oyster Interior. I guess one of the first things I should do is, appreciate I'm lucky enough to be able to own such a bucket list car.

[scm]

2017 (MY18?)

Check the 10th digit of your VIN for the MY - if it's J, you're MY18.

[MM1963]

It's a 'J' by jove! Thanks scm (again)