Access your Linux Files(especially your videos with thumbnail or preview) from your android phone

1. Install samba in your Linux

https://ubuntu.com/tutorials/install-and-configure-samba#2-installing-samba
Don't forget to create a user with the same name as your curretn Linux username: sudo smbpasswd -a your_username

2. Install Solid Explorer in your android phone

https://play.google.com/store/apps/details?id=pl.solidexplorer2

3. Add your samba server to your phone

Click Solid Explorer right-bottom 'add button'
->
Click 'New cloud connection'
->
Select 'LAN/SMB'
->
Select your server
->
Click 'Username and password'
->
Fill it with the username and password that you have created before
->
Click 'Next'
->
Done!

4. Use Kodi is also a good idea

sudo apt install kodi
add samba server to your kodi: https://kodi.wiki/view/Adding_video_sources#Adding_Remote_sources
fix language problem: settings -> interface settings -> skin -> fonts -> arial based