Welcome Loinerlad,
Nice model launch you've acquired. First thing you have to find out is where you're going to sail it and if they allow internal combustion engines, many places are now putting a ban on oily. noisy propulsion.
First recommendation is to use a local hobby shop if that is practical, there's often free advice available regarding suitable purchases - the second is to find a local club if one exists - going it alone is feasible but sharing a hobby is always better - once again, free advice and help usually available there.
For basic radio set-up, an in-expensive two channel (function) set is all that would be necessary to control your model. Try using the search facility on this site to answer most of the questions you'll have that people will have already answered - this site is a mine of useful information.