I use OpenWrt for the first time.
Please help me how I can configure two VLANs like this
You need to provide more information, as which VLAN you want Ethernet ports for and which you want Wireless only, is one of them for guests, or both for your use.
Anyway, this document about VLAN
https://openwrt.org/docs/guide-user/network/vlan/switch_configuration
An this is about guest WiFi
https://openwrt.org/docs/guide-user/network/wifi/guestwifi/guest-wlan
MIKROTIK
Vlan 101 employees and devices like tplink
Vlan 102 guests (hotspot)
OK, for VLAN101, all you need to do is go to Network > Switch and change VLAN 1 to 101 (that's presuming you have good reason to want VLAN ID to be 101, otherwise just leave it as it's.
For the gusst network, if you don't need any LAN ports and you don't have a good reason to want VLAN ID 102, you could just create a guest WiFi as described in https://openwrt.org/docs/guide-user/network/wifi/guestwifi/guest-wlan
Which hardware version of the TL-WA901ND do you have?
It looks like the V2 has a direct physical ethernet port. On that one you would define VLANs in the physical settings there is no switch to configure.
Model
TP-Link TL-WA901N/ND v4
Architecture
Qualcomm Atheros TP9343 rev 0
Firmware Version
OpenWrt 18.06.2 r7676-cddd7b4c77 / LuCI openwrt-18.06 branch (git-19.020.41695-6f6641d)