Which wallet is good for beginners and use it for long term ?

I have started freelance job a month back and I received my first pay as crypto USDT Now I have 2 questions ( better safe then sorry )

What wallet is good to have ( can’t afford ledger ) a cellphone based wallet The reason I’m asking, is I couldn’t do a kyc based and I just created a wallet without kyc and received my pay, but I’m not comfortable with having wallet with no KYC and want to know which wallet is best to use for long term

My second question is I am getting paid in USDT and I saw a lot of people talking about not to keep asset as USDT What shall I do ? Shall I convert to other coin or just keep them USDT, because according to employer the USDT is stable coin but what I have been reading that stable coins are not that safe

If anyone is also getting paid in crypto for remotely job, please share your experience on which wallet using and what form of crypto you’re keeping Thanks