Hi kittu,
looking at your forum history, I can’t help but feel that you ask the same basic question every few months… could it be that you are searching for something to help you tie all those loose ends together?
Every real life project you may wish to tackle requires peripherals which is hardware, so you need to become clear about what hardware you are able to/ want to build your sample project on. Typical stand-alone projects that fit the bill would be sensor driven systems such as weather stations, smoke detectors or very rudimentary model train controllers. Those must also fit your personal preferences and intersts, of course.
Then again, very few embedded systems these days exist without host communication channels to concentrators, smartphones or PCs, typically network or UART based, so you should pick a target hardware also with that in mind.