Ok @Number12, so if you have it (or think you might) it would be best if you isolate yourself from the rest of your household. Can you do that?
Then you need to drink lots (really lots - tea, squash, juice, water) and rest. Take vit C and d and zinc every day if you have them.
If it is COVID then it would be useful if you had some way of measuring your temperature (ie a thermometer) and some way of measuring your breathing (look up Roth test unless you have a pulse oximeter or peak flow meter) and pulse.
Other than that, paracetamol, tissues and cough sweets - but you may not need any of them, it can be very mild. And if it isnt, post on here for support.