sorry but my cat went over the keyboard and has probably changed some presets so that the image of LR 5 (left no presets, right no tools, version has changed to LR 4 from LR5.7) came up different. I asked Apple to do a backup which is possible but suggest to ask Adobe because Apple does not know where the responsible datas for LR are.
Please check the below Presets Location for Lightroom
Presets and templates
Windows: C:\Users\[user name]\AppData\Roaming\Adobe\Lightroom\[preset or template folder]\[preset or template filename.lrtemplate]
Mac: /Users/[user name]/Library/Application Support/Adobe/Lightroom/[preset or template folder]/[preset or template filename.lrtemplate]
How to backup presets for Lightroom
Let us know if that helps.
Sounds like your cat just stepped on the TAB key to hide the side/top panels.
Just press TAB again to restore them