Hello Devalakhi,
If you plan to crack the UCEED examination, without any coaching, the first thing you need to know is the exam pattern, what type of questions come in each section and what is the marks distribution. Coming to the UCEED examination, it tests the candidate on the following parameters:
Visual and Spatial Ability, Observation and Design Sensitivity, Environmental and Social Awareness, Analytical and Logical Reasoning, Language and Creativity, Design Thinking and Problem Solving.  So the questions will be based on these parameters. What I suggest is that you go through the previous year’s question papers and try an understand the type of questions which come. Master a few topics and try and solve as many questions as you can. Try and form your own perspective on a few popular design concepts. You also need to be updated on current affairs and various environmental and social issues. Solve as many analytical and logical reasoning questions as you can. Start with the easy ones, and gradually move onto the difficult ones.

In order to understand in detail the exam pattern of UCEED examination, you can click on the following link

https://engineering.careers360.com/articles/uceed-exam-pattern

P.S. I would advise that only if you are confident enough and think you can prepare a timetable and the material on your own and stick to it, only then you should go opt for self-preparation, otherwise you should go for coaching. If you go for self-preparation, you will have to make your own timetable, and even prepare the material yourself. A coaching class will provide you will all the necessary material and you will save a lot of time.

I hope this was helpful and all the best!