Hi,
I am new with BTC and I've read now a lot of threads about the topic "unconfirmed" or "stuck" transactions. Problem is: I sent the BTC six hours ago. I used the normal, standard fee. Now I read I should have used more, with dynamic what I will do the next time. First Question: Can I "cancell" the transaction and give more fee? Than it will probably faster?
Unless you are in a hurry in most cases it is easier just to wait it out.
Seconds: when I update linux/electrum is there a possability that I "loose" btc?
Make sure you write down the seed and store it somewhere safe. As long as you have your wallet seed you can't lose your bitcoins.
Also: when I change the server, could I loose it?
The worst thing that can happen is that the server feeds your wallet incorrect transaction data and then you act on that and lose money/property because of it. But electrum takes steps to make that hard to do so it highly unlikely.
After some hours a new problem is coming up now: in the lower left is always staning: "Synchronizing ..." nothing changes. Should I maybe get a other version?
I can be patient, if it will be sent in some hours, than its no problem. I just want to know, if a made a mistake
You should upgrade to the latest version because it has support for dynamic fees which make transaction confirmation delays much less likely.
The servers we all rely on are run by volunteers so they do sometimes go down. You can try switching to another server via tools > network. Also may be donate to the server operators
. You can see their address on the console tab.