Morph with aghs is really good against universal heroes, so generally, you want to pick him against enemies that pick that. But honestly, morph outscales almost any carry with aghs anyway, especially since linken's can be popped through BKB now.
In lane morph is still really good because of essence shift. You have to abuse that you can trade with the enemy to low hp, just go down to 0 strength, morph up a bit of strength again and thus be at 50% health again.
Also, currently adaptive strike is maxed first most of the time, because it can be spammed (only 40-70 mana!) on the enemy offlane and bully them out of lane (or at least contest heavily). Even against the typical vanguard buyers. You also either buy cornucopia or morbid mask because you often want linken's or satanic, which lets you stay in lane even better. And lastly, you're really good with healing lotus (and magic stick), because when you go down to 0 strength and pop one, you heal a huge percentage of your HP.
Item build is pretty dynamic, you want linken's first if you have a problem with stuff like duel, but mostly manta, especially if the enemy has dispellable disables like silences. If you don't go linken's first item, then definitely get falcon blade first before manta, otherwise you have no mana. The next item is most always agh's, because it's your biggest powerspike. And then look what you need, satanic, skadi, daedalus, bkb, etc.
Skill build is also not completely set in stone, you want to generally max adaptive strike first, but you also often want 2 points in essence shift for better survivability, and if you either bully the enemy hard or are bullied hard yourself, you want to skill waveform instead of adaptive for the farming speed.
Morph is a pretty hard hero to learn because his abilities are not completely straightforward. Don't be afraid to show up to fights with your huge survivability, but remember that you can also be killed quickly if you mess up with morphing too far into agility or not having your wave form to escape. Just practice and I'm sure you'll get it down :)