If I were you starting out I would recommend . ...........
1 sebo bs36 vac £300 new, they come in a very smart royal blue now, used £100
1 electric sprayer £120 from window cleaning warehouse
1 rake any cc supplier £25
1 used buffer w/soft brush and pad holder from a forum member less than £200, maybe get some pads thrown in
10 pads nuway from restormate £300
1 airflex mini -for stairs,upholstery and the odd extraction job , £1300 new inc vat but free training.
Chems , a general cleaner(restormate/solutions cornwall are my favourites) some spotter, a good coffee remover , some solvent gel and that is it , no more than £200 will allow you to carry out £5k of cleaning to start.
Some cleaners mate software £250
A website from carpetcleaning websites.co.uk £300 . this includes optimization , or ask on here there are a few very good cleaners/web developers who will make a good site and get you on page one of google .
Using your car will be fine with some magnetic signs ,all the above will fit in it easily . My Transit van only cost me £1500 inc signwriting and pays for itself in ad revenue, and obviously gives a better image.
There are much more accessories, chems and bits and pieces that suppliers and other cleaners will say that you need at start up, you dont though . You need to get cash in the door and re invest until you have a decent monthly turnover.
I always aim for one regular returning customer every month added to my business, the type that spends from 1-5k a year , mostly these are commercial customers , who have multiple sites which need cleaning , think property managers , housing associations , lettings agents , private landlords, wealthy or particular private homes, I have customers on rough council estates who have me every month to do this or that job , maybe £50 or £60 a time , but it is no fuss or hassle and those customers are as valuable long term as a blue chip account, who may take an age to pay or be really fussy about times/access/ paperwork etc.
Also I NEVER turn down a job , and am always willing to diversify if the capital needed is not too high , as well as carpets I clean , upholstery, inc leather, curtains, fires, floods , grafitti, windows, hard floors , inc tile and stone and trauma scenes, drug houses, vacant clean and clears , end of tenancy cleans. Dont worry all these can be added over time , and take little extra spending to add if you are careful.