Hi I'm new here and I would like some input. I'm 5"6' and 173 lbs. I am currently wearing size 8 pants and medium shirts. I have lots of fat to lose but I'm exercising and building muscle. I really wondering what my goal weight should be. I'm excited to get to know everyone.

Only you can answer this, unfortunately! You could get to 150 and look super lean, or you could get to 150 and be smaller, but still "soft". Weight fluctuates with water retention, time of day, etc. Maybe you could shoot for a goal weight RANGE and combine it with fitness goals, pant size or body fat percentage.

Maybe start with something in the middle of the normal BMI chart and then adjust it as you get closer.

Weight is only one measure of fitness. For those of us with a lot to lose, like myself, getting weight off is the first thing to focus on as there are so many health benefits to losing the weight. I think a weight goal is really helpful to me for now. Once I get in the 175 range I'll probably do some adjusting to my plan. I'll certainly be planning to lose slower than I am now, and maybe I'll want a lower final goal or be satisfied with a higher one.

Thanks!! I really don't want to be a softer 150. Lean 150 would be great.

I agree with everyone. In the beginning we always decide that we want to get as thin as models are or we decide to not lose enough because we're afraid we won't make it.
Then most people decide to not meet their initial goals. You can't know beforehand what you'll look like when you reach your goal. You can't know how you'll do with your diet, etc. You can decide on a number if you think that it will motivate you (I like to know that I lost x lbs and still have y left) but you'll figure it out as you go.