Intermediate weight trainer need advice not sure what to do anymore?

[GIBuild]

Up until July of 2011 I have never worked out before never did anything upper body at all. So in July I joined my local gym for the first time.
I started out with a membership that included a personal trainer, he showed me lots of stuff my weight level increased real fast the first 2 months
but over the last year I have made no improvements at all. Not only that but I have lost some mass and have some pain in my shoulder that has
healed a little but not totally. I'm also developing tendentious on my left arm. So I really need advice on what to do?
I do some bench pressing not much though like 90 pounds, barbells 30 pounds. I can do chin ups with 70 pounds off my weight.
I know most likely I'm doing some of the exercises with improper form, which I have watched some videos on youtube to fix that.

So what I need to know is what kind of program can I do to work Biceps, Triceps, Chest and shoulder without hurting myself and that will work out
all those muscle groups.

What exercises should I do to hit most of the muscle groups?
How many reps and sets should I do?
How many different exercises per muscle group should I do I'm not sure what is enough for one day?

I normally do 2 sets 12 reps each I do a variety of exercises with machines too like the Incline Press, Bicep Curl, Tricep Press, Real Delts.

I almost feel like giving up sometimes I feel so out of place compared to everyone else that I see working out.
If you need any info from me let me know. I appreciate any guidance.

[msm172021121]

Up until July of 2011 I have never worked out before never did anything upper body at all. So in July I joined my local gym for the first time.
I started out with a membership that included a personal trainer, he showed me lots of stuff my weight level increased real fast the first 2 months
but over the last year I have made no improvements at all. Not only that but I have lost some mass and have some pain in my shoulder that has
healed a little but not totally. I'm also developing tendentious on my left arm. So I really need advice on what to do?
I do some bench pressing not much though like 90 pounds, barbells 30 pounds. I can do chin ups with 70 pounds off my weight.
I know most likely I'm doing some of the exercises with improper form, which I have watched some videos on youtube to fix that.

So what I need to know is what kind of program can I do to work Biceps, Triceps, Chest and shoulder without hurting myself and that will work out
all those muscle groups.

What exercises should I do to hit most of the muscle groups?
How many reps and sets should I do?
How many different exercises per muscle group should I do I'm not sure what is enough for one day?

I normally do 2 sets 12 reps each I do a variety of exercises with machines too like the Incline Press, Bicep Curl, Tricep Press, Real Delts.

I almost feel like giving up sometimes I feel so out of place compared to everyone else that I see working out.
If you need any info from me let me know. I appreciate any guidance.

I wouldn't call that "intermediate". How long have you been lifting? Have you been doing the same routine the whole time?

[GeneralSerpant]

If you could get some formal training for the Barbell Bench Press, and Seated Cable-Row, that would be a good start.

Otherwise, do some curls, triceps-extension exercises, pull-ups/chin-ups, sit-ups, etc.

[GIBuild]

I wouldn't call that "intermediate". How long have you been lifting? Have you been doing the same routine the whole time?

1.5 years I have switched different exercises here and there I started doing the bench press 6 months ago. I guess I'm more of a basic.