It does seem very complicated ?
Can you play this at home or do you have to go to a venue?
There are all sorts of systems available with varying complexities in just about any setting (fantasy, historical, science fiction, naval, aircraft, spaceships) and scales from pub punch-ups to Waterloo. The best systems let you concentrate on actual tactics and putting yourself in the position of a commander, while Games Workshop stuff is much more about meta-gaming to exploit an ever changing set of special rules and trick units, then setting up and rolling huge handfuls of dice without much by the way of actual decisions or tactics once you're playing.
You can play at home, the problem these days is finding folk near you to play with who are interested in the same settings and systems as you. That's where Games Workshop shines, they have retail shops and run tournaments where you can use the hugely expensive models that they sold you, and God help you if you try and bring anything else.
You could jump on... urgh... Facebook and see if there are any Localtown wargaming / tabletop clubs.
From when I actively played the meta in the tournament scene changed monthly. And learning your own stuff wasn't enough you needed to know everyone else's tricks to know where mis interpretation existed.
True that, I once reduced a grown man to tears in a tournament by exploiting the hell out of Epic with a force composed entirely of cheap Scout Marine companies and Thunderhawk dropships (part played by de-bladed Micro Machines Apache helicopters from the local toy shop). He deploys. My whole army is off table. Turn 1, Thunderhawks drop from orbit to any point on table, and deploy swarms of Scouts directly into close combat with his expensive Titans and super-heavies. Then comes the Epic cheese of "Titan stomps on Scouts, next stand is +3, Titan stomps on Scouts, next stand is +6, Titan stomp on Scouts, next stand is +9, wins, reactor hit, boom."
Rinse and repeat until by the end of turn 1 he's lost all his big stuff, and he's trembling and choking up and saying "But all you're doing is trading your cheap units for my expensive ones!"
Life is hell in the grimdark, chap.