Me And My Mate Are Trying To Plan Business Ideas But We're Struggling For Ideas

So currently I'm in high school all this could change sijce we're high school teens eho have never lived in the real world

So my mate is intending to go to the army college in London when he turns 16 then he'll come back up north for a gap year and then going back into the army

My plan (I have semi pitched to him ) is that we make a business Idea I set it up while he's at the army college and then we run it together till he goes to the army and he keep a small bit of ownership . Other plan to get rid of the business when he goes or sell it off . This means we can do our interail travel around Europe idea .

This idea would have to be online so we can do it while travelling also doable by one person . Mainly this is because my mate will have basically no money for the trip and I'd rather not be the one paying for everything

If it's profitable I'll keep it going if notcill sell it or just shut it down . It'd need ls to be enough to buy food , a couple nights in a premier inn and then the bills he'll have to pay in the couple of weeks we're gone