You sound like me when i first started asking questions lol, slippery slope my friend. Ive had an inferno, so here goes, simplicity ftw
Decent shampoo, cheaper the better to an extent, imo
Some decent polish, tripple from auto finnese would be a winner.
Wax or sealant if thats your thing. Tough coat from auto fineese and probably a sample of dodo juice £6 ish
And some microfibre cloths, cheap as chips on amazon, ebay etc
You dont come accross as the next detailing king so the above should do you,
Cost £40 ish...