I have RB2011U wireless MikroTik router and 2 old Linksys routers. I want to connect mikrotik to WAN and then two other Linksys routers by cable. The first Linksys to Mikrotik and the second Linksys to the first Linksys. Does it require something more than typing PPoE login and password? I will create wifi-s on those two Linksys routers. Is there anything more I will need to do on MikroTik?

Depends on your goal. If you are going from router to wan on linksys 1 and then lan on linksys 1 to wan of linksys 2 you'll need to make sure all three routers are on different subnets. As far as the mikrotik is concerned it will be setup out of the box as a basic router so you wont need to change anything unless you are looking for a more advanced setup.