The classes could be really good I used to go to a gym that did PT classes so there were 6 of you getting help from a PT and I really enjoyed it. Lots of the classes I've gone to usually try to fix your form a little bit
If you have the time and space you could do a home workout? There are lots of great things on YouTube and you can use things around your house for weights. Also joining a gym and going to classes is a fun way of starting and making friends 😊 Or, you could find a gym buddy to go with you? 😄
Most gyms will offer a free PT session and they can show you some exercises and how to do them correctly. Also agree with classes!
Maybe try using chatgpt. It sounds silly but it's free and can come up with a custom plan for you based on your goals, maybe find a gym you like the look of, have an introductory tour most of them offer this, then for your first session just use the treadmill to get a feel for the machines and types of people, attending the classes if they have them is always good too!