there are multiple ways
1. selling a small amount.
bitcoin is always good investment in long term. when we say "hodl" we don't mean for a week or a month, it is much longer than that. and you should always invest money that you don't need so you don't HAVE TO sell.
imagine if you had bought 1 bitcoin when price was $3000. in order to get your entire investment out with its equal profit (meaning $6000) all you have to do today is to sell 0.1160BTC and hold on to the rest 0.8840BTC.
obviously the more you invest the more you gain and the longer you hold you also gain more.
2. the traders approach
there are lots of times when price reaches a high and needs a correction. most of them are also easy to predict and detect too. the size of the corrections are also the same most of the times.
selling on those highs (again like first point selling a small amount) then waiting some days for the drop to slow down then buying back the same amount of bitcoin you sold will leave you with a good profit.
3. spending bitcoin
you don't always have to sell to take the profit you can always buy stuff with your bitcoin, again like first point. you want to buy something that is worth $6000 you can pay with 0.1160 bitcoin.
and lending your bitcoin is not a good idea and it has a lot of problems that most people don't want to deal with such as defaults or scammers including the platform you use for lending.