Have a look on YouTube, there’s loads of workouts you can do at home that don’t really need equipment. Do burpees/squat jumps, running on the spot, star jumps, press ups (loads of variations to have a go at), dips, sit ups/crunches etc. Burpees are the absolute best thing ever if you dont have cash to waste, loads of variations and every one of them killer. Do as many as you can in a minute, rest for 30secs/a minute and repeat. Do that 5-6 times and keep a log of how many you do so you can see yourself getting better.
Go for a run, join a running club or a club of some sort that you just pay a couple of quid a go for, have an ask around for a local group that does cross fit or something, much better than some crappy gym!
Exercise does not need to be in a gym, get your head around that, you’ll be fine. You only need to do 30 minutes a day, you can certainly find it in the hrs you are working!