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? 😄
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!