If you've not got the budget/knowledge to go all out .. ( £2-300+ for machine, polishes, pads, and other things you need etc etc etc)
... then if I were you I'd buy some nice shampoo and a wash mitt from CYC/I4D and maybe some quick sealer to top up protection. £20/30 tops all in. ((Microfibers too.. wheel cleaner, tyre gel, glass cleaner and a drying towel maybe some new buckets) OK maybe £50..)
Then, I'd pay someone local to give it a spruce up with a machine. Say that's £100-150 (rough guess for a non-pro), if you wash the car properly and don't use gritty yellow sponges, that should do you for a year at least. My car was last polished over 2 years ago and it's only really starting to show signs of needing a real small correction again.
What colour is the car ?