What's your educational background? What is your occupation?
In general, if you have a professional job but haven't got higher education beyond a bachelor's degree (although it seems to me that most "professional" jobs in the US require more than just a BA/BS), your category is more likely to fall under EB3. If you have don't have college education, but have the minimum of 2 year work experience, then you are also going to be put in the EB3 category. Unskilled or semi-skilled workers will also be put in the same EB3 category. Looks like EB3 is a very broad category..
BTW there are also EB4 and EB5 (I used to think there are only EB1, 2 &3) and so look at info about these categories at the USCIS site, too, just in case!