i have DSL with static Ip and 20 clients how i configer my mikrotik kindly help

Add ip, gateway, dns to the external - internet interface(ip->address/routes/dns). Check connectivity to internet from router using ping or tracert(tools).
If you want dynamic ip's to clients use dhcp server setup(ip->dhcp server) if there is dhcp, then go to system->packages enable dhcp and reboot router.
Finaly add masquerade rule in ip->irewall/nat.

Dear brother could not understand kindly explian in detail