Hello, there! I am not an expert but structuring my experience and brief research that i've just made I would say that these are 3 main options that seem to be useful (at least they are often recommended)

First one (AI and Automation) There are well-known tools that can assist in detecting common security flaws and coding errors. Top 2 for me are MythX and Slither . They are specifically engineered to find bugs, security issues, etc. This involves scanning the code for known security vulnerabilities, abnormal patterns, and unexpected behaviors that may indicate the presence of bugs.

Second (Auditing): Find some professional auditing firms or individuals with expertise in smart contract security to conduct thorough audits. These audits typically involve in-depth review and analysis to identify and remediate bugs.This guys - Cyfrin are for sure my favorites in the field. (I really think that in terms of security if you are newbie it's better to ask for some help)

Third (Try using bug bounties) Consider participating in bug bounty programs where security researchers can identify and report bugs in exchange for rewards. Platforms like Immunefi offer bug bounty programs for smart contracts. May be something like Immunefi can help: This project provides bug bounty and security services for smart contracts. Their platform allows developers to offer bug bounties and security incentives for finding and fixing bugs in smart contracts.

However I think that if you have some time the best solution would be attending some educational courses. There are tons of them starting from Udemy all the way up to Chainlink.

Have a good one, would greatly appreciate any insights if you've already found another solution!