Roast chicken is my thing.
I get a large roasting dish (big enough for chicken and roast potatoes), sprinkle some olive oil, then plonk the chicken in one half of tray, with a halved lemon or 2 in the cavity. Sprinkle with more oil, salt and pepper and pop in oven at 180.
Meanwhile, peel and cut to desired size of potato, pop in a pan of salted boiling water for 5-8 mins ish. Drain, give a toss to rough up the edges. Take chicken out of oven, tilt tin for juices to run to the empty side, then tumble the potatoes into the empty half. Use tongs to turn each potato so it's coated in oil, and season.
About 50-60 mins later, it should all be done. You could turn the potatoes again half way through to get more even colour.
Check juices in thickest part run clear, remove lemons, and move chicken to a carving board. Move potatoes into their final dish, pop back in oven to keep warm.
Squeeze out the lemons, then slowly tip out the excess oil from the roasting tin (I keep an empty jar for this purpose). Put the tin onto the hob, and deglaze with some white wine, add some cornflour mixed with water, and keep stirring to make your gravy.
There's other stuff you can do, but those are my basics 😄