I do just now notice the pinned topic in this forum by Mr. PG "Here’s a no-brainer ....install Cakewalk and the TTS-1 64 bit" that suggests TTS-1 64.
Community thoughts? Even if one doesn't use the DAW, this might be an easy 1 step solution.
The TTS-1 is an excellent GM sound source. Note since you indicated that you are a novice in MIDI I would start by only looking at GM sound sources.
Another excellent GM source are soundfonts (SF2). VirtualMIDISynth is an excellent SF2 player:
https://coolsoft.altervista.org/en/virtualmidisynthThere are a ton of different SF2s available. An advantage is you change sounds in a SF2 buy using an editor:
https://belnln.colorfulkitchen.co/free-soundfont-editor/For example if you don't like the sound of a sax you can change it with a new sax sound.
Note that there are a number of excellent soundfont players and librarians available.
I just wanted to show you another option. There are others options available, I just don't have any experience with them.
I hope this helps.