How do i fix my lanos starter ?

I've had alot of issues with this car, recently, leaking heat matrix and the petrol pump stopped working. THey all been fixed but now the car starter motor seems to be failing, sometimes it works no problem, other times there's the sound of the engine trying to start but not catching and other times theres a clicking (loud clicking sound) and that it...I'm not the most mechanically minded person, anyone got any basic advice (seriously basic, i have no clue about engines, but as I'm unemployed I need to try deal with myself) as to what to check, what could be the problem,