Indwelling catheter urine sample

Hello,

I am in my first clinical rotation (med-surg) and am quite stupid about so many things. I had to obtain a 10 ml urine sample from an indwelling sample (my preceptor was not with me). I got a 10 ml syringe and needle and inserted in the port. The needle kept coming it out of the port. At what angle should it be inserted so this doesn't happen and I don't puncture the tubing?

Also, I couldn't get 10 ml initially (too much air). Should I have gotten a new syringe/needle combo to get the remaining amount or could I still use the same needle?

Thanks for your help!