A quick check of the basic`s first, are you sure the battery is ok, some will have enough power to run the lights and turn the motor a few times but then lose there power, if you can try using a battery charger with a jump start setting if you diconnect the battery and just use the leads from the starter if it starts ok try another battery.
If the battery appears ok then check the earth lead fom the battery to the starter and also the power lead from the battery to the starter solenoid. if both are ok you may need to look at the starter, you may feel better if you can get a mechanic to look at it from here on as taking the starter apart and checking the brushes can be a bit fiddley.Let us know how you get on.
Hope this helps Skip
Do the best you can with what you have,
A stranger in a strange land now heading North South East West to.....