Sick:

Rest: Get enough sleep and limit physical activity to give your body time to recover.
Drink plenty of water: Water helps the body eliminate toxins and replenish fluids lost due to fever or cough.
Using over-the-counter medications: Painkillers such as paracetamol or ibuprofen can help relieve symptoms such as fever and aches.
Use saline solution: Saline solution can help clear your nose and throat.
Avoid contact with others: If you have a cold, stay home to avoid spreading it to others.
Footsore:

Rest: Avoid activities that put pressure on the painful foot.
Ice: Apply ice to the painful area for 15-20 minutes at a time, several times a day.
Elevate the leg: Elevate the affected leg above the level of your heart while lying or sitting.
Wear comfortable shoes: Choose shoes that have good cushioning and fit your feet properly.
Use over-the-counter pain relievers: Pain relievers such as paracetamol or ibuprofen can help ease painful symptoms.
Stomach-ache:

Drink plenty of water: Water helps the body eliminate toxins and replace fluids lost due to diarrhea or vomiting.
Eat bland foods: Choose foods that are easy to digest, such as toast, bananas, and white rice.
Avoid spicy and greasy foods: These foods can aggravate stomach pain.
Use antidiarrheal medications (if needed): Antidiarrheal medications such as loperamide can help relieve diarrhea symptoms.
Rest: Get enough sleep and limit physical activity to give your body time to recover.
Note: If your symptoms become severe or do not improve after a few days, see your doctor for proper diagnosis and treatment.

In addition, you can refer to some general health advice below:

Eat nutritious food.
Exercise regularly.
Get enough sleep.
Reduce stress.
Avoid smoking.
Drink alcohol in moderation.
Go for regular health checkups.