When it comes to training:
Firstly, if you can find a gym and want to continue training... get stuck in!
If you want to lower your training frequency, try training 2-3 times per week and opt for "full-body" style workouts where you train the main movements for each muscle group a few times per week.
If you won't be training in a gym, consider packing some resistance bands and skipping rope!
I like to do HIIT style workouts, starting a stopwatch for 20+ minutes and rotating between 5-6 exercises, 40 seconds of work and 20 seconds rest (40:20) in a circuit style! (or 30:30)
You can choose to do 1 exercise for each body part for a full-body workout, or do chest & back, shoulders & arms, and legs & back one day after another with a rest day in between (3 days on, 1 day off).
When it comes to nutrition, there are a few things to look out for:
1. Cheap and convenient sources of protein: tinned tuna, yogurt/soy yogurt, sliced meat, etc.
2. Foods that don't require a kitchen or cooking to prepare: oats (also very cheap), bananas, dark chocolate, rice/corncakes, nuts and seeds, etc.
Usually when you eat out, carbohydrates and fat are easy to find on the menu. Enough protein to meet daily requirements... not so much.
That's why I usually base the meals I don't eat out around protein.
When eating out, first of all... enjoy yourself! Once again, look for dishes with reasonable protein content. If you're looking to limit your calories, fats are where they lie.
Chefs are heavy-handed with oil, butter, and the like because it makes food taste so damn good! Try to limit dishes where sources of fat are key ingredients for a low-calorie option. Think lean protein and carbs.
An easy way to manage your calories abroad is intermittent fasting. This also reduces the frequency of your meals - meaningless eating out or less planning.
You can read all about intermittent fasting in my book "The Fasted Lifestyle" which is linked at the bottom of this email.