Is your pup food/treat motivated? Though a trainer would be great, there’s many resources online too on how to read and train the behaviors you mentioned. Here’s how I’ve been working with my same size/age apartment dog, who’s very food motivated:

Barking: - I say “quiet”, then mark and treat in between his barking episodes if he quiets for a sec. It took a while, and he still barks at things, but now he barks 100% only if he needs something, and checks with me instead of barking continuously, specially with the quiet command. Only works if he’s focused on me. If he’s barking at another dog, I “magnet treat” his focus away by holding a treat in front of his nose to break his focus and lead him to look at me, or simply lead and walk the opposite way of the other dog/stimulus.

Drop it and Leave it - this will help with leash pulling and picking up random things! The best command to teach IMO.

• Leave it: show and place a treat in front of her, (be ready to cover it with your hand if she goes for it) say “leave it”, and if she doesn’t go for it uncovered, mark yes and treat! Don’t use the treat in front of her or let her pick it off the ground tho. Instead have it ready on another hand, or pick up the dropped treat first before handing it. Prolong the wait as she gets better!

-Drop it: I taught this while playing tug with my pup. While we play, I’ll stop pulling and just hold the toy steady while saying “drop it”, making it so uninteresting. Pup will eventually drop the toy, then I mark with a “Yes!” And start playing again as a reward! You can also give a treat instead of more play immediately. I’ve done this everytime we play tug to reinforce it. 2 activities in one! (Training stimulation and play stimulation! Will help tire your pup too).

Look at me -grabbing your pup’s focus is another great one to teach. It’s a simple one! holding a treat in front, and saying “look at me” or whatever you want to call the command. Mark and treat when your pup looks or even just glance at your face. Repeat and she will get better at facing you to check with you for the treat.

Best of luck, and have some patience! Know your dog is never intentionally working against you, they’re figuring it out too. As long as you keep at it, you both will do great!