If exchange fees on Exodus are cutting into my earnings and age limits restrict many platforms, should I be focusing more on wallets with lower conversion costs, or reconsider whether converting to USD is even the best approach for my under-18 crypto setup?

I need an open-source and multi-chain Bitcoin wallet, so suggest some reliable options, and also tell me what the main security concerns are to consider when I am selecting a wallet with infrequent updates or inactive developer communities.