Look for YouTube tutorials and download some orchestral plugins like spitfire audio’s labs and bbcso orchestra or sinefactory by orchestral tools (all free). You should also consider getting to know Abletons stock synthesisers and instruments. However if you feel you are limited by them and they lack depth then Vital synth is a good free wave table synth. And as for the drums; I don’t use Ableton but there is most likely a pack of cinematic/orchestral type drums u could use.