looking for opinions on getting in the trade

Hey guys, so recently i started applying for refrigeration jobs in my area, as well as applying for my local UA union in my city that my dad also works for as a pipefitter. I'm looking for opinions whether i should wait for a call back from the union or keep applying for other companies in the area. My dad speaks very highly of the union so i lean towards waiting it out but im eager to just get started and get any experience i can. Im also wondering if it smart for me to get my safety tickets prior to getting a job. For context i do NOT have any experience in the trades and have been working in retail for 4 years, and i have a license with a clean record for 4 years.