Welcome to the family MC in these trying times. Sounds like you have a nice pond there and a willingness to learn.... that will be a fun ride, there are a lot of smart folks on here to help guide you in the right direction. Ask lots of questions and the experts will also ask you to provide information on types of fish ( catch some and take pix of them for id and go from there . My opinion of tilapia is that they will get rid of a lot of filamentious algae while helping to feed predators with their own young , I don’t think they harm other fish