What do I do for statistical analysis for my science fair project data?

If you have never done any statistics, telling you to do "statistical analysis" is a completely fatuous suggestion. It is not something you pick up in 10 minutes by looking it up. And if it is not required for the exhibition, then it would be a waste of time anyway. How many people seeing it would understand, or be interested, in it ? And unless it concerns something of vital importance or significance, sophisticated statistical analysis is not adding anything of value. The best thing you can do is to present your actual data in as interesting and eye-catching way as possible. Without knowing what the subject actually is, I can only suggest that for each group you construct a graph, or bar chart, whichever seems most appropriate, showing the change in the variable over the 6 days. Make each chart or graph a different color, but all to the same scale, for easy comparison. Point out any differences between groups, and suggest the reasons for them. Make sure that you understand all the material on display, and can talk about it intelligently to anyone who asks about it. Keeping things simple and easy to understand is much more likely to attract interest than apparently abstruse and complicated mathematics which no-one understands. (And what do you say if anyone asked you what all the fancy analysis means, if you do not thoroughly understand it yourself ? It doesn't look good for you !)