It doesn't matter if you searching for articles to support a presentation you have to deliver to the class, or to design a poster around a topic, or to write an essay / do your final year dissertation - every search should be done in a systematic way.
So it should be planned out and organised - don't just jump in and start searching randomly
It should have limits set on it - this is so that you don't have to wade through every result you get for your key terms
Your limits should be reasonable and justifiable - think about the impact of any limits you set. Should you really be choosing full-text articles only when you're doing your dissertation? Should you really be limiting to UK only when international articles / methods are referenced and used just as much as UK papers in your discipline?
You do need to factor in how confident you're feeling, where your skill level is set currently but, as you progress through the different stages of your programme your skills should improve and develop which should then have a positive impact on your confidence level.
And if you get stuck there are many workshops and help guides that you can use to help you. You can also use the Library chat system to talk to a member of library staff and get some help directly.