January is the worst time to join a gym as it will be a passing phase - you should start making small changes to your lifestyle each week.
Step 1 - start to walk, jog, run or combine all three.
You need to do this three times a week.
The first mistake people make is that they think they need to run / walk as fast as they can to lose weight - WRONG
You need to work within your target heart rate zone - here’s a simple way to calculate this:
Assume you are 45 years old
220 - age = maximum heart rate
220 - 45 = 175bpm, this is your maximum heart rate
Now we need to work at 70% of this
175 x 70% = 122beats per minute
The best way to monitor this is to get yourself a basic cardio watch (about €50) and you will see that you will not have to go that fast to hit your target heart rate.
The key is distance not speed - try and make each session 1hr long, maybe 1hr 20 min if you have the time.
Now off you go and work on this before looking at the next tip.