If you don't know your colours, which ones look best with your skin tone, try to find out; maybe try on some scarves to get an idea?
Generally brighter colours ( tops, scarves) look better as we age.
Avoid beige, black and greys, greige, and pastels next to the face.
These 'neutrals' generally do older skin tones no favour, and make one look older and somewhat 'invisible', and who needs that?
Nice coloured scarves can be useful for a pop of colour, next to the face, as well as being warm.
Stick to classic style in trousers and jeans, or really, whatever style feels most comfortable and 'goes with' the style of tops/jumpers, and especially foot wear you feel best in.
Find a good fitting and comfortable jacket or coat, one that makes you feel good going out in it, as mostly that's what people see ( and you see) when you go out.
The right colours can do a lot to make a change, and you can source out trousers, jeans, jumpers and tops, footwear and outerwear in thrift shops ( which is actually fun to do if you've not tried it) it allows you to try all kinds of different styles, without committing to a steep layout of cash, and of course, clothing is easily tried on and obtained in the many shops.
Find a good haircut that goes with the tiime/energy you have to devote to it, and keep up with trims. I'm sure with a few simple changes, you'll feel better about your appearance @Lifelover16 and Good luck!