Welcome to the world of gardening, three years in for more and it is addictive. Perennials might be better in the trough (plants that die off every year but grow back) maybe with a couple of evergreens. I am reading your trough as being a raised bed, ie permanent rather than something moveable ?
How exciting! The only other thing I'd add is that if you pick some plants you like and put them in, some will do very well and some won't (because they're in the wrong amount of sun/soil type etc) and not to be disheartened. Just get more of the stuff that's happy! )
Trough - Pick out the stones and other grot and empty the trough. What you fill it with depends partly on what you plant and also on whether it has any drainage holes in the bottom. The best thing to fill it is a mix of general purpose potting compost and John Innes compost (which has more nutrients). Both are available at garden centres. If there is no drainage at the bottom of the trough, add a layer of crocks (broken flower pots etc) and mix some grit into the compost so it doesn't just turn to mud in wet weather. Then, decide what you want to plant in it. Bedding plants are available at most supermarkets at this time of year, as well as at garden centres.
Patch by front door - Get rid of the biggest stones. Pull/dig out as many of the weeds as you can. Buy a piece of weed-suppressing/landscaping fabric (again from a garden centre) to fit the square, put bark or stones on top and the pot on top of that.
If you can tell us what sort of things you like - pastel and pretty? bold and architectural? - we can even suggest what plants to buy!
But I have a wall separating my patio and garden which has a trough of dirt in it, full of stones and crap! How would I go about putting plants in there? Do I need to dig it out and put new soil in there? Can I buy bedding plants of any sort? Where from?
Also I have a square patch by my front door full of stones and weeds. I would like a large pot here with a large plant/tree in it, I can picture it in my mind but don't know what to buy. Could I just fill the area with bark or stones to put my pot on?
Thanks from a complete idiot . I mowed a lawn for the first time in my life last week and now there's no stopping me