First of all, I think it is a very good idea to buy in the market now because after all of the coronavirus thing, together with the BTC halving event, the market, in my opinion will recover to hopefully a new high. As for the transaction for cash, you'd have to probably resort to meeting in a public space, face to face, having some security in place and do it that way. Cash transactions are less easier to do since it takes a little more effort!

Good luck, though!