A one year child, while quite active with the hands and legs, is in the discovery phase, everything is new and exciting. Putting things in the mouth or feeling crevices through is their way of experiencing their world.
At the same time, they are definitely aware of when their parents are happy with them and when they are not. They also try to take actions that make the parents happy or get them engaged in a positive manner with the parents.
Try to move the child away from the objects, look them in th eye and change your voice intonation (without raising it too much) to let them know if there is a behaviour you are not happy about.
Similarly praise them with a smile or hug when they do something positive, like walking or crawling, or keeping things in their right places. They would like to repeat behavior that gives them positive feedback.
Try to keep a positive to negative feedback ratio high 5:1 perhaps. So look for reasons to praise the child. Saying, yes, yes goes farther than no, no. This means you have be on the lookout for positive behavior - it's so much more difficult to spot!
At the same time there are some dangerous situations where you simply have to take immediate action, for example if the child is about to reach out to the sharp edge of a knife, or touch a hot iron or put his fingers in the electric socket. Attempt to keep the home child safe by removing access to these scenarios and if they do occur the first task of the parent should be to remove the child from that situation, it can be included with a loud voice and a loud no. This acclimatises the child to stop doing whatever they are doing (like trying to cross a road without assitance) when they hear you shout in the future.
Let them get away with as much as they can. It's the discovery phase after all. Involve them in tidying up once they make a mess, so putting things back in their places becomes an interesting activity.