This appears to be rule 305.7, which I got from: Gamepedia.
305.7. If an effect sets a land’s subtype to one or more of the basic land types, the land no longer has its old land type. It loses all
abilities generated from its rules text, its old land types, and any
copy effects affecting that land, and it gains the appropriate mana
ability for each new ...
This is Comprehensive Rule 113.6:
113.6. Abilities of an instant or sorcery spell usually function only while that object is on the stack. Abilities of all other objects usually function only while that object is on the battlefield. The exceptions are as follows:
[ ... ]
113.6k An ability whose cost or effect specifies that it moves the object it’s on out ...
Yes, you can cast as many spells as you want on the same creature.
The targeting requirements for Tactical Advantage are that it must be a creature you control, and it must be attacking or blocking. Tactical Advantage changes none of these properties, so the second Tactical Advantage is just as legal to cast as the first.
If you can identify the card, you can simply look up its English text in Gatherer. The following helps you achieve that.
First of all, if you are able to type in the name, just search for the name using Scryfall. It accepts non-English names (in part and in whole). Typing the name without accents works.
If you can scan or photograph the card, another easy ...