Take a rest after running, not too long, and then go to the elliptical machine for a while. The speed can be adjusted at any time according to your physical condition. Decide your own time. Don't take too long. After all, it is the first exercise, and the body should have an adaptation process.
You can go cycling the next day. Generally, there are cycling classes in gyms, which are basically free. Ask if you have it. If you have them, you can ride with them. You can minimize the resistance when riding. You don't have to do some actions in the process. You can ride with them. The first time you can't keep up with the coach's rhythm, just stick to your own rhythm.
On the third day, if you can swim and the gym has a swimming pool, go swimming. Swimming is also a very good aerobic exercise, which is very effective for losing weight and fat. If not, run a little and get familiar with other equipment. There is also the shame of asking questions, asking old members and coaches. Girls in the gym are still popular.