@cloudy That sounds really tough, and I just want to acknowledge how valid your feelings are. Starting your first job is a huge transition, and it’s completely normal to feel lost, overwhelmed, or even lonely at times. Many of my friends have expressed similar struggles when they started working—feeling like they didn’t know enough, worrying about asking too many questions, and feeling anxious about whether they were good enough. You are definitely not alone in this.
One thing that might help is getting to know the people around you—not just in terms of work, but also personally. Try to join colleagues for lunch when you can, or just have casual conversations with them. It makes a big difference when you start to build connections, and over time, you’ll naturally find people you feel more comfortable reaching out to. 
Since you’re not sure who to ask for help, a useful approach might be to find out who’s been around the longest. Even if they don’t have all the answers, they usually know who to direct you to, which can be really helpful. And when you do ask for help, you might be surprised—many people are happy to share their knowledge, and as long as you’re putting in effort to learn, they likely won’t mind.
Also, please be kind to yourself. It’s natural to feel like you’re not doing enough or that your best isn’t good enough, but learning and growing take time. You’re still adjusting, and that doesn’t mean you’re not capable. You got this job for a reason, and over time, things will start to feel more manageable. Hang in there and jiayou—you’re doing better than you think!