We need pictures, and measurements and even then probably can only guess at possible answers.
The Clarke CLV20RV is from a cast flatbed, so probably wouldn't fit on a tube frame without a lot of changes. However if it is that the spindle should be 6" above the bed and have an MT2 (morse taper size 2) IF your headstock does not have an MT2 then your tailstock probably didn't either, they almost always match!
To be brutally honest it is not a good lathe, it is a budget machine that the brand new equivalent is under £200.
SO whatever you do, do not spend a lot fixing it. Go with a bit of faceplate work, join up with your local club see if there is some training available, that will get you access to tools and a better idea of what is required, and scan the adds see if a replacement tailstock comes your way. At the same time compare prices of second hand fully working lathes to the cost of fixing yours.
My first month or so of turning was on someone else's lathe before I even had a roof on my workshop, guidance is invaluable as well as being the best way not to overspend on things you do not need but also how to be safe, and get a result that will encourage you to continue.