Corrections in red. Stylistics in blue.

A place what I Would Like to Visit

I would like to go to Spain. I think that if you are going there for the first time, you should to visit Barcelona, to see a match with Real Madrid in person, and to ride the large roller coasters in PortAventura. I have never been in Spain, so I would like to visit [1] Tossa de Mar because it is a beautiful, old, small town with historical buildings. It is situated on the seacoast. There are many restaurants featuring local cuisine and real Spaniards!  Tossa de Mar is not far from Barcelona. A favourite place for tourists is the old city in Barcelona. There you will find four of the oldest parts of Barcelona, with their gothic buildings.
If I had [2] enough free time, I would [2] walk to local markets and to Guelle Park. I could [2] also watch a sunset at the park. And the best place for me to be at dawn is the beach!
I know there is a very interesting restaurant in Barcelona, called the Torre d'Alta Mar. It is situated at the top the old port's cable tower. It has a breathtaking view opens there. It is very romantic, I think! And I hope I could [2] bring back a lot [3] of photos and good experiences from Spain

[1] Every dictionary will tell you that the English word for отдыхать or отдохнуть is "rest". However, in English, rest usually means the almost complete cessation (stopping) of activity in order to regain your strength. "I run 10 km, then I have to stop, stand still, and rest. I work hard all day, then I lie down on the couch to rest." If you go to a sea resort or the forest, a better word may be "relax". When you "relax", there may be more activity than when you "rest". When you go to another city, and walk around, and do a lot of things, I would probably not use either word. I might say, "I would like to visit X" or "I would like to go to X and do some sightseeing."

[2]  You have to use the conditional mode.

[3]  "a lot of" or "lots of", but not "a lots of".

place what I would like to visit

I would like to go to Spain. I think if you go there first time you should to visit Barselona, to watch match Real Madrid on live(вживую) and ride the highest roller coasters in PortAventura.I have never been in Spain so I would like to rest in Tossa de Mar because it is a beautifull old small town with historical buildings. It is situated on the sea cost, there are many restaurants with local cuisine and really spain people. Tossa de Mar is not far from Barselona. A favourite place for tourists is old city in Barselona. There are 4 the oldest parts of Barselona with gothic buildings.
If I have enough free time I go to walk to local market and to park Guelle. I also can watch a sunset at this park. And the best to be at dawn is beach for me!
I know there is very interesting restaurant in Barselona, its caled Torre d'Alta Mar. It situated on the top in tower cable way. It is breath-taking view opens there. It is very romantic, I think! And I hope I can bring a lots of photos and good experiences from Spain