Connects are no longer free. You have to buy them. The Plus plan gives 70/month or you can buy them for $0.15/connect. I wonder if they give you 20 free when you join.
You can search the forums and online for general tips. I found this tip on Reddit. Constantly browse the job listing and apply to jobs immediately. I keep upwork on my phone. When new jobs show up, apply immediately, Usually 10-30 minutes after the job was posted. This generally gets me within the first 5-10 proposals.
I tried this last week and got three small jobs from it. I recommend doing this on small jobs first. That way you get enough jobs for a job success score.