I'm planning to resign..

Hello. 25F and I was just hired dito sa first corporate job ko. I was really dreaming of getting a job sa field na to kasi I really enjoyed doing it. Pero after 3 months, I feel like I didn't have proper training/onboarding to do my job properly. FYI na I'm a business graduate and my current work is related to IT. So, as someone na walang kahit anong background with IT processes, I don't know what to do most of the time and they want me to learn by experience. I do get them pero most of the time that I want to ask questions para matuto, I'm afraid to mess things up or ask the wrong things. I don't feel like I'm also supported by my manager and I know na he thinks lowly of me kasi I'm not able to live up to par with their expectations of me kasi ang hirap talaga. Need advise guys. Thanks.