Dota 2 Advice?

Well every hero has the suggested items on the left side of the shopscreen, but for some heroes they are well.. made badly. You just have to learn how you want to play your hero and what he needs. It just a learning curve really.

Some advice kid; kill lots, die less.

But as far as build go, depends on what role you like to play. Don't build supports as carries cause they really havent got the damage to back them up, let your carry get kills etc etc Basically just common sense and time really.

Just look some guides I prefer these channels. It helps o lot.

DotaCinema

dota2cast

dotatwocast

check out playdota website for guides for dota heroes. they are basically the same in dota 2.

I'm new to Dota 2 as well. Never played any Dota, HoN or LoL before so everything is new to me. I started by trying these guides against bots first and then moved using them to public matches. Read the two guides for noobs; Learning the Ropes - A Begginers Guide to DotA and [Updated] The Little Things, Tips and Tricks | BoredomIsFun .
http://www.dotafire.com/dota-2/guides?sort_type=score_weighted&sort_order=&hero_id=&min_quality=&max_age=&min_vote_count=0

After that pick a hero guide and go practice that against bots and practice your last hitting. Also Purge's Youtube channel was useful to me to see how he plays heroes. He posts guides for heroes.
http://www.youtube.com/user/PurgeGamers/videos

Also I would recommend checking out pro matches ( http://www.youtube.com/user/joinDOTA/videos ) and streams of pro players http://cs.twitch.tv/directory/Dota%202 and http://www.own3d.tv/game/Dota+2 for example)