Is there any way to tag places on Google map, so I can memorize them for future?
Yes, just longpress a point on the map and a 'Dropped pin' card appears bottom of screen - drag it up to give options - tap the star to save the location which will show a yellow star when you view the map.
If you tap the 3 dot menu button top right you can add your own label to the location.
The saved location is in 'Your places' in the menu accessed by either swiping from the left or tapping the 3 bar munu button top left. It will be in 'Labelled places' and/or 'Saved places'.
I find it's better to use the label option, because unless the dropped pin is at an identifiable address the saved location will be in latitude/longitude form and if you have a number of saved locations it's not easy to find the one you want whereas with 'Labelled places' it is straightforward.