Doctor can order a test on routine physical with bloodwork and urine. You’re also pseudo tested for blood bourne STDs when you donate. I recommend all of us get an annual physical and to donate blood at least once a year.
You can also go to planned parenthood in some states. They will test for STDs, and is fully covered by your state government.
If you wear condoms for all sexual contact, the chance of contracting the major STDs is infinitesimal bordering on impossible. STDs are transmitted mostly by unprotected sexual acts such as bare BJs, and high risk acts such as anal sex where condoms are likely to not be used or are shredded in the act. Even while bare backing, vaginal sex isn’t that likely to transmit from female to male.